What are the reasons for the non-responsive central locking system in a 2009 Passat?

[DiDaniela]

2009 Passat central locking system not responding includes the following reasons: The smart key does not respond when pressed, and the main driver's door does not respond when pressed. If the smart key does not respond when pressed, it may be due to an issue with the smart key. The most common situation is that the key battery is dead, and replacing the battery usually solves the problem. Low battery power can also cause this issue. Even if the smart key light is on, it does not necessarily guarantee sufficient power. Weak power may barely keep the light on but is insufficient to transmit signals, preventing the central locking system from locking and unlocking. Interference sources near the vehicle. Check if there are any signal interference sources around the vehicle. When inspecting wireless signal faults, ensure to rule out any additional wireless signal devices installed on the vehicle. Faulty circuit board inside the key. Motor aging requires replacement, blown fuses in the switch circuit need replacement, faulty central locking system main unit needs replacement, loose linkage rod of the main motor requires tightening, etc. These issues need to be addressed at a repair shop.