Diplomat model ABA 9242 Integral dishwasher. starts programee ( i.e 1 Rinse ) pump runs to drain water then changes to draw water in through inlet hose. Stops & bleeps ( 1 beep every 30 sec's) Upon opening door, about 1 " of water is in the bottom tray & illuminated indicator ( on top side of door ) Flashing
E 4. No leaks, & all electrical wiring seems intact ??

michael leonard, September 2017

https://www.justanswer.com/uk-appliance/2vba8-diplomat-aba-9242-dishwasher-stuck-e4-displayed.html

Have you checked inside the base?

If there is no water in there now, check the float switch isn't jammed up

Acp, September 2017