Detecting faults in subscriber telephone lines

A method for detecting an incident or fault in a subscriber line including the step (172) of performing electrical measurements, CHARACTERIZED in that the method comprises: a) the step (175 or 176) of determining an auxiliary variable based on the electrical measurements through probabilistic relations encompassed in a first classifier; b) step (177) to determine whether the line has a problem or failure based on electrical measurements and the auxiliary variable through probabilistic relations encompassed in a second classifier.