, this dishwasher, while seeming to operate and wash OK, will not stop washing when the door is opened. The customer wasn't sure when this odd behavior began since most loads are started and the door isn't opened until the end of the cycle. But one day while trying to add a dish during a wash cycle that had just been started, the door was opened and water went everywhere. Knowing that wasn't correct, it was time for service.
Dishwasher door latches will have one or more interlock switches that are used for the purpose of cutting power, and/or informing the control board when the door has been opened. These can be wired in series with the wash pump or other load components preventing current flow when the door is opened. Or as in this model, can be used as a monitor circuit to tell the control board the position of the door latch.
When the door on this model is opened, the interlock switch contacts will close completing the monitor circuit back to the control board. Continuity through the circuit tells the electronics the door is open and to stop operating. When the door is closed, the switch contacts will open, thus opening the monitor circuit which the electronics will interpret as the door being closed.
The interlock switch on this unit was operating properly which leaves the control board as being the component that has failed. Mechanical switches, like the one mounted in the latch assembly are more likely to fail, but on this unit, the control board was the problem. Installed a new control board assembly and now the dishwasher stops washing when the door is opened.