| 摘要 |
PURPOSE:To exactly judge failure of an exhaust gas recirculation equipment by increasing a count when reflux of exhaust gas takes place, or decreasing the count when no reflux of exhaust gas takes place, and comparing the temperature in an exhaust gas recirculating path with that at the time of starting the count when the count value becomes a specified value or more. CONSTITUTION:Based on the detection values sensored by an intake air temperature sensor 19, a throttle opening sensor 21, a water temperature sensor 23, a car speed sensor 25, etc., a control circuit 10 judges whether or not the EGR- operation is carried out through an EGR control valve 9, and increases the counter when the EGR-operation is carried out and decrease the counter when the EGR-operation is not carried out. When the count value reaches a specified value, the control circuit calculates a difference between a detection value sensored by an exhaust gas temperature sensor 17 installed downstream the EGR control valve 9 in an exhaust gas recirculating path 8 and a detection value at the time of starting the count, and judges that the exhaust gas recirculation equipment is defective if the difference is less than the specified value, thus causing an alarm lamp 28 to light. |
