What are the reasons why a vehicle's mechanical lock cannot be opened?

[NatalieLee]

The reasons why a vehicle's mechanical lock cannot be opened are: 1. The lock core drive rod has come off; 2. The door lock latch is faulty, with the internal spring broken or stuck; 3. The vehicle's central locking system is in the electronic locked state; 4. Incorrect operation - turning the key clockwise unlocks it, while turning it counterclockwise locks it; 5. The lock core is faulty; 6. There is an issue with the mechanical key. The vehicle mechanical lock is a device installed on the door and its pillar that can reliably lock the door and achieve opening and locking functions through its internal mechanism. It is an important body accessory with safety protection functions. The method for replacing the lock core of a vehicle mechanical lock is: 1. Use a flat-head wrench to pry open the rubber cover on the door, revealing the hexagonal screw; 2. Loosen the screw and remove the door lock core assembly; 3. Pull out the old lock core by gripping the outer handle lock core cover and pulling it outward; 4. Install the new lock core by following the original steps in reverse order to complete the replacement.