While you wait for answers, we may have found some information which could help you.
Click here for Dishwasher E4 FindWhy is my SMEG Dishwasher showing E1 without water in tray?
How to fix Kenwood Slimline Dishwasher KDW45X20 with a F1 Er?
How do I turn the delay off on Electrolux DX302 dishwasher?