THEFT PREVENTION SYSTEM IN AN AUTOMOTIVE KEYLESS ENTRY SYSTEM WITH AUTOMATIC DOOR LOCKING

摘要

A theft preventive system, in an automotive keyless entry system with automatic door locking, is adapted to produce an alarm signal in response to door opening when the theft preventive system is in a door-locked position, and which is cooperative with a door-lock system but independently operable in order to switch its operating mode from a door-locked mode to a door-unlocked mode. The theft preventive system in an automotive keyless entry system, according to the present invention, includes a push-button-type function key for operating a door-lock mechanism to lock a vehicle door. A memory circuit is responsive to a door-lock signal fed from the door-lock function key to indicate the door-locked condition. The content of the memory cannot be cleared unless a plurality of door-unlock function keys are properly operated. An alarm circuit is responsive to a door-open signal from a door switch in the presence of a memory output indicative of the door-locked condition to produce an alarm signal.