Why anti-theft not working for BMW x5 3.0i 2004?

The anti-theft system in a 2004 BMW X5 3.0i may not be functioning due to several reasons, such as a dead key fob battery, a malfunctioning immobilizer, or a fault in the wiring or sensors. Additionally, if the vehicle's battery is weak or disconnected, the anti-theft system may not engage properly. It's also possible that the system has been inadvertently deactivated or is experiencing software issues. Diagnosing the problem typically requires checking for error codes and inspecting the system components.