Cancel Drain on Bosch dishwasher simply wil...

Model SHX43C06UC/48 Bosch built-in dishwasher less than 6 months old has gotten stuck in needing cancel drain function, but no matter what we do, we cannot get it to activate.  When we open the door and press on/off, the unit is already running, making that loud start-up sound.  Followed the Cancel Drain procedure in manual to the letter and then in every combination we could think of, i.e. holding the buttons down while turned off and then on, holding down cancel drain for longer than 3 seconds, trying to change out of regular wash cycle after delicate button blinked while regular wash cycle was lit, etc.  Every obvious thing has been checked like a clogged drain, obstructed vent, top rack not seated correctly.  This happened when we first got it and the repairman who came out got the cancel drain function to work right away even though we had tried to do the same thing the night before.  Please give idiot proof, "Cancel Drain Function for Dummies" style instructions.