locking signal

例句：

1. 1.The car's engine is producing a loud noise when it starts up.
   汽车启动时发出很大的声音。
2. 2. The security system has a locking signal that alerts the police if someone tries to break in.
   安全系统有一个锁定信号，如果有人试图闯入，就会报警。
3. 3. The new software updates have a locking signal that prevents unauthorized access.
   新的软件更新有一个锁定信号，防止未经授权的访问。