When the engine is in a specified operation state in which the EGR valve is brought into the full-close condition, the holding force for holding the EGR valve at the full-close position is corrected by correcting the control duty signal of the EGR valve. The latch plate supports the weight of the furnace door in a closed position and reduces a pinch force used for rotating the knob. The ETC system provides an adjustable engine idle speed and an engine power limiting feature.