Here's a thought. Don't know this DW at all but if it is an older model that has a mechanical mode switch with a small synchronous motor driving contact blades via a cam, then the problem may lie there. Why I think so is that was the fault with my old Speed Queen washing machine that failed to complete a spesific cycle. The reason being that contact blades were so eroded that they no longer made electrical contact to complete the cycle. Being a mechanical switch I could advance the cycle manually by turning the control knob by hand. My local domestic supply & repair shop could refurbish the timer. But this answer is academic however if yours is an electronic model.