JPS6337742B

PURPOSE:To prevent miss setting due to over turning of key cylinder in unlocking direction when drawing a key, by providing a timer means in settng operation controlling means while providing means for prohibiting reset during operation of timer means in the theft prevention controlling means. CONSTITUTION:Setting operation controlling means A will perform confirmation of parking operation and unauthorized crew and decide whether the conditions for setting the unauthorized intrusion waiting state have satisfied. While theft prevention controlling section B is set to unauthorized intrusion waiting state by means of said means A and reset by means of reset operation control means C to detect unauthorized intrusion on the basis of an open/close signal from open/close detection means D thus to produce an alarm. The control means B includes means B1 for prohibiting reset of detection means C during operation of timer means A2 thus to prevent erroneous function of theft preventer.