PURPOSE: To achieve control while cooperating among the systems of amount of control when recovering one system by comparing the output values of a control advance angle priority circuit of a self system and another system and then releasing the break when the difference is within a certain value.

CONSTITUTION: '1' is output by detecting abnormality when a control device 100AA fails in an abnormality detection circuit 31AA but it is also output to another system and the output of a flip-flop circuit 32AA is set when the output of the abnormality detection circuit 31AA is in '1' and a switch 37AA is operated. Then, only a control advance angle priority circuit 28AB is input to a selection circuit 50AA but the output value of the control advance angle priority circuit 28AB is selected since two input values are equal. Also, a comparison circuit 36AA compares the output value of a control advance angle priority circuit 28AA with that of 28AB and then outputs '1' when the difference is within a certain value. A similar operation is made even if the abnormality detection circuit 31AB of another system operates.