If the error is still showing then you haven't fixed the problem. Don't know what you have done so far but E4 usually means it has over filled & flooded. Probably still has water in the base tray holding the float switch on which will signal the E4. Pull dishwasher forward from under bench. Put some towels around on floor at rear of dishwasher then tip the dishwasher back as far as you can & see if water comes out. Once the water is out E4 will go away & dishwasher will run. If it comes back at some later date then you will have to check further to see if it is leaking.
Lincoln Appliance NZ, December 2014