One day the "Lock On" LED on our Kenmore Dishwasher is lit, and the dishwasher won't start.
I find:
I follow the suggestions, remembering that I'd done something like this, successfully, once before.
Then I remember the key step. You have to disconnect the controller-to-front panel ribbon cable, THEN close-up the cover and inner door, FINALLY Close The Door!
You won't see anything happening, no LED, and the buttons don't work. All disconnected.
BUT, if you then open it all up and reconnect the ribbon cable, then close it up again, in 2 out of 2 cases, the "Lock On" LED will be out and the dishwasher will start and run!
Its not just disconnecting the power cables from the controller board, opening the circuit breaker to the dishwasher, or disconnecting the ribbon cable from controller to panel.
You must disconnect the ribbon cable, then close the door so the controller powers up without the panel connected, power down, reconnect and power up again.
Just like you were troubleshooting whether it was the controller or the front panel. Its BOTH, but if you disconnect them, it will clear.