Hi , still having problems with my central locking on E Class 1997 E300TD. The NSF door, NSR door and OSR doors will not lock or unlock and all three airlines from the doors operate from one point on the central locking pump. Is it possible for this part of the pump to fail and the rest of the pump to continue to work? Need to know as a replacement pump is an expensive option.Could there be another reason for the fault?
Thanks
FrankB

 

replace the pump.