I had the E90 problem about a year or so ago. Havng had a problem with my Zanussi dishwasher a common fault with zanussi white goods is that they don't solder major joints on the control boards very well. (Probably tryng to economise of the amount of solder they use)
Check all the connections on the control board are tight and haven't burnt off the solder. This worked for me and we haven't had this code since.
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