Programmed this m/c up for 80mins 40 degrees wash. At 68 mins the m/c just stops and will not progress any further, except every now and again it will suddenly burst into spin and tumble or a few second then it stops again. Checked heater ok and motor seems fine whilst on spin. Never come across this fault before on an AEG.
Have had problems with AEG motors cutting out on thermal o/l on long programmes. Sounds like tacho problem that you describe though. Check wiring & plug connections to motor & board as they suffer from duff connections every now & again. Have you checked brushes & armature?