Volkswagen MK4 Golf Central locking issue 

Got a strange problem on my mk4 Golf. The central locking stopped working on the driver side door out of nowhere.
When I enter the car and put the key in the ignition the puddle light on the door turns on and turns off when I close the door. (this tells me that the switch in the door is working fine)
After putting my key in the igniton I can lock and unlock all doors without issues, but only for like 10 secconds. Could this be a door lock problem or could there be something else faulty. I don't want to replace the door locking module when something else is at fault.
I can lock and unlock my car from the passanger door without any issues.