diplomat adp8500/1/2, start and programme light flashes ?

the machine pumps out residual water after pressing the start button, then as its about to start the fill cycle both the start light and the programme light flash together off and on about ten times at about 1 second intervals, then it will pause and then flash both lights again for about the same period,you can hear it start to fill but stops as the lights go out i've checked the filters, the arms are all free and the door switch is working properly, any ideas??