E90 is a communication error between the user facia control board and the programme pcb inside the appliance ~ this can be caused by the buttons on the front panel getting dirty/sticky and not depressing or releasing correctly. Clean buttons and try again. Otherwise unplug machine, remove lid , remove facia and strip down to fully clean buttons etc. Ifb this still fails pcb's / wiring may be faulty.
Nigel (FWM Repairs), September 2005
