Electronic control unit for monitoring a microcomputer

An electronic control unit for controlling an actuator with a microcomputer, comprising:

• a monitoring circuit including an assignment number selecting unit for selecting an assignment number, a communicating unit for transmitting the assignment number selected by the assignment number selecting unit to the microcomputer and receiving an answer from the microcomputer, and a comparing/judging unit for comparing the answer with a correct answer to check the function of the microcomputer,
• wherein the assignment number selecting unit renews the assignment number to a next assignment number when the answer and the correct answer are judged to be coincident with each other in the comparing/judging unit, and selects the same assignment number as a next assignment number when the answer and the correct answer are judged to be non-coincident with each other in the comparing/judging unit;
• and
• the microcomputer performs a predetermined self-function check operation in accordance with the assignment number received, and transmits an operation result as the answer.