| 摘要 |
<p>PROBLEM TO BE SOLVED: To judge the abnormal condition of an electric heating type catalyst regardless of change of an idling rotational speed of an engine. SOLUTION: It is judged whether current IECH and voltage VEHC supplied to an electric heating type catalyst (EHC) are within a prescribed upper and lower limit values IMAX, IMIN, and VMAX, VMIN (S1, S2), abnormal condition of the EHC is judged (S5) when it is the relation of IEHC>IMAX or IEHC< IMIN or VEHC>VMAX, or VECH<VMIN so as to stop to supply power to the EHC. The prescribed upper and lower limit values IMAX, IMIN, VMAX, VMIN are set according to an engine rotational speed NE.</p> |
