Wash Keeps Running. All Night.

Just over a year old. This Unit will start just fine. We here the motor running. Come back the next morning, and it is still in wash mode. Open the door, and there is steam and suds in the bottom. Hit start again, close the door, and it goes back to wash cycle. It never ends. I wonder if the heating element is too hot, and maybe the thermocouple is not reading correctly. What else could prolong the cycle?

Thanks for any help Eric Becker