Door Lock Vacuum Hose
 

Hey I have a 1997 Audi A4 1.8 t and i recently have a problem where all my locks only open and close manually...when i hit the lock on the driver side i can hear what seems to be the compressor pump for the vacuum line of the door lock hose from the trunk of the car. Does anyone know how i can fix this hopefully its just a loose hose or maybe its cut somewhere but ive yet to hear any hissing indicating a leak somewhere..As well as im having a tough time locating the pump if anyone has any advice plz let me know..pictures would be a bonus!! thanks for your help