[Solved] Electrolux EES69310L Dishwasher Error d:0n - MachineCare Program Issue & Cleaning Procedure

Good evening everyone,
I have the following problem. Before starting the MachineCare program (a program to clean the dishwasher), I cleaned the dishwasher manually (as in the manual) and when starting it, strange symbols appeared on the display: d: 0n (more precisely in the picture). This symbol appears every time I start the device and it has stopped working properly since then. It does not run cleaning programs at all (neither itself nor the dishes). I close the dishwasher, and after a minute it opens itself, claiming that it has already been washing for several minutes (e.g. when I turn on the 30-minute program, the dishwasher opens after a while and the timer shows 15 minutes). I would like to ask for help what could have happened to the dishwasher. Of course I looked at the manual.

Can someone tell me how to enter this diagnostic mode on this model?

Check the user's manual, it looks like some feature is enabled, not a bug. Diagnostic mode is unlikely to help you here.

Problem solved. I called the hotline. It turned out to be a demo mode, used to show the dishwasher not connected to the water supply. Hold down the ECO and AUTO buttons simultaneously for 5 seconds, the message d will appear ff and everything works as it should. There was no mention of it in the manual.