OK, thanks for that.
Integrated makes it harder to sort out.
Basically, e15 indicates the anti flood device in the base of the machine has been activated, so you have had a spillage or leak of water from the tub, into the base.
If it was a spillage, it shouldn't happen repeatedly, unless it's overfoaming on every wash.
To check and possibly rectify the problem, you need to gain access to the base of the machine so you can drain the water out and then run it with the panels off to check for a leak.
If you don't fancy taking the machine out, and if you can find proof of purchase, call Siemens.
You have, at least, a 2 year warranty on the machine.
Speak to them, see what they have to say about the repeated failure.
They should come out and sort it out for you under warranty.
If you do want to do it yourself, unplug the appliance.
Take it out of it's integrated position and take the side panels off.
Sponge all the water in the base out.
Once out, run the machine on a wash and watch it working.
You need to locate and cure the leak to rectify the problem..
If you find there's a lot of foam inside then you need to sort out the rinse aid side of things.
If you use all in one tablets and rinse aid you are overdosing on rinse aid.
This causes foam and ultimately the problem you are having.
Check it out, see what you find and get back to me if you need more help.
Hope this helps