| 摘要 |
<p>When a measurement trigger which is outputted at an every predetermined time after start of an engine is detected, a sensor outputting a signal in relation to concentration of a liquid reducing agent on the basis of a characteristic of heat transmission between two points apart from each other within the liquid reducing agent storage tank is triggered to measure concentration of the liquid reducing agent. Each of the number of times of determination of no liquid reducing agent, that is, the number of times concentration is successively determined to be equal to or higher than an upper limit threshold, and the number of times of determination of a solution of a different kind, that is, the number of times concentration is successively determined to be equal to or lower than a lower limit threshold is counted. When the number of times of determination of no liquid reducing agent becomes equal to or larger than the predetermined value, it is determined that no liquid reducing agent remains. When the number of times of determination of a solution of a different kind becomes equal to or larger than the predetermined value, it is determined that the liquid reducing agent is a solution of a different kind. When the number of times of determination of no liquid reducing agent and the number of times of determination of a solution of a different kind is less than the predetermined value, it is determined that the liquid reducing agent is correct one.</p> |
