Patent ID: 8135515

Claim:
A VGRS electronic control apparatus, which receives an input of an electric signal from a sensor indicating an operation amount of an actuator of a variable gear ratio steering device that varies a ratio of transfer between a steering angle of a steering wheel and a steered angle of steered wheels, calculates a detection value of the operation amount based on the electric signal and controls the variable gear ratio steering device in accordance with the detected value, the VGRS electronic control apparatus comprising: a microcomputer mounted on a substrate with other electronic circuit elements, wherein the microcomputer includes two CPUs, each of which calculates the detection value based on the detection value, a ROM, which stores two detection value calculation programs having same processing contents for calculating the detection value, and a comparator, which compares processing results of the two CPUs, wherein the two CPUs calculate the detection value by using one of the two detection value calculation programs and the detection value by using the other of the two detection value calculation programs, respectively, wherein a first detection value and a second detection value are compared, the first detection value and the second detection value being the detection values produced by executing the one and the other of the two detection value calculation programs, wherein the two CPUs calculate intermediate values by executing a plurality of processing, which form the one of the detection value calculation program, in executing the one of the detection value calculation program, and intermediate values by executing a plurality of processing, which form the other of the detection value calculation program, in executing the other of the detection value calculation program, respectively, and wherein the comparator compares the intermediate values of the one of the two CPUs and the other of the two CPUs, each time the two CPUs calculate the intermediate values by executing the one of the detection value calculation programs and the other of the detection value calculation programs, respectively.