Patent ID: 6845315

Claim:
An engine air-intake control device according to this invention includes: a driving switch element that is connected in series to a motor, which controls an opening of an intake valve of an engine responsive to a detection output from an accelerator position sensor and a throttle position sensor, and controls a conduction current of said motor; a power supply interruption element acting as a load circuit power supply interruption element connected to a power supply circuit of said motor, or as a control circuit power supply interruption element connected to a conduction controlling power supply circuit of said driving switch element; a drive control circuit for generating a conduction drive output in order to control conduction to said driving switch element responsive to a detection output of said accelerator position sensor and throttle position sensor; a monitoring control circuit that is connected via a serial communication circuit with respect to said drive control circuit, and monitors operation of said drive control circuit; and status signal detection means for detecting an operation state of said driving switch element and said power supply interruption element, and for supplying a status signal corresponding to the operation state to said drive control circuit or said monitoring control circuit; wherein said drive control circuit and monitoring control circuit cooperate with each other in accordance with a result of detection of said status signal detection means to generate in a sharing manner a feed drive output in order to bring said power supply interruption element into operation, a feed-inhibit output in order to make said feed drive output reactive, and a conduction-inhibit output in order to make said conduction drive output reactive, whereby said outputs are caused to perform an operation stop or an operation permission of said power supply interruption element and said driving switch element.