A drive controlling unit includes a final angle position memorizing device for
memorizing a final angle position at a time of termination of the vehicle driving
operation, an input complete data memorizing device capable of switching the memory
content between a first memory condition and a second memory condition. The first
memory condition indicates completeness of writing of the final angle position
in the final angle position memorizing device. The second memory condition indicates
failure in writing the final angle position therein. The input complete data memorizing
device is capable of maintaining the memory content even when the vehicle is stationary.
