Patent ID: 7612464

Claim:
An electronic control apparatus for a vehicle comprising: a microcomputer including an actuator controller and a controller monitor, the actuator controller working to control an operation of an actuator mounted in a vehicle in response to an input signal indicating a parameter associated with a preselected operating condition of the vehicle, the controller monitor working to monitor validity of a monitor parameter, associated with an operation of the actuator controller and being obtained thereby with computation by the microcomputer, by comparing the monitor parameter and an expected value of the monitor parameter, said controller monitor working to monitor whether the actuator controller is operating properly or not based on the monitored validity of the monitor parameter, said microcomputer outputting the monitor parameter and the expected value of the monitor parameter; and a monitor module including a digital circuit which is designed to monitor whether said controller monitor is operating properly or not based on comparison between the monitor parameter and the expected value of the monitor parameter, as inputted from said microcomputer, without the monitor module transmitting a test signal to the controller monitor of the microcomputer for monitoring the controller monitor, and to output a signal indicative thereof to an actuator driver; wherein when a period of time in which the monitor parameter continues to be different from the expected value of the monitor parameter exceeds a predetermined time, said monitor module determines that the controller monitor is malfunctioning; and said monitor module is equipped with a data error counter which counts up in response to input from a plurality of clocks, as used to determine a reference speed at which the digital circuit operates, and is cleared upon agreement of the monitor parameter with the expected value of the monitor parameter, and wherein when a count value of the data error counter exceeds a preselected value, said monitor module determines that the period of time in which the monitor parameter continues to be different from the expected value of the monitor parameter has exceeded the predetermined time.