| 摘要 |
<p>Provided is a competency diagnosis system for a urea water temperature sensor that can limit diagnoses during a cold start. The competency diagnosis system (129) for a urea water temperature sensor has a competency diagnosis unit (127) for comparing the temperature of urea water measured by a temperature sensor (121) provided in a urea tank (105) to the ambient air temperature, and diagnosing faults in the temperature sensor (121). The system has a cold start condition assessment unit (128), which, when an engine is started, determines the difference between the engine coolant temperature and the ambient air temperature, the difference between the engine coolant temperature and the fuel temperature, and the difference between the ambient air temperature and the fuel temperature using the measured engine coolant temperature, ambient air temperature, and fuel temperature, and permits diagnosis by the competency diagnosis unit (127) in cases when each of these differences is at or below pre-set thresholds.</p> |
