I wanted to close the loop on this post to maybe help someone else. So I had this dishwasher sitting in my garage for the past year and a half unable to diagnose or repair it. I pulled it out recently to make one last attempt. I ended up finding another door mounted temp sensor and swapped it out, but same symptom - It wouldn't advance through the full cycle. A couple of calls to Miele and they said either the door mount temp sensor was bad or the control board was bad. Not willing to give up, I ended up finding a thermometer I had with a remote sensor I could put into the dishwasher as it ran. The thermometer revealed it was only getting up to 122 degree F max. Since the temp setting says 150 degrees, it wasn't getting hot enough to trigger the door mounted sensor.
The heating element is a silver tube running up the left side and there is a surface mounted sensor half way up the tube with two wires running to it. I bypassed this sensor thinking it might be bad and ran it again. Same symptoms and still only getting to 122 degrees max. I believe this sensor is a override circuit breaker type sensor that will shut the heater off if it gets too hot. Looking further, there is another sensor/resistor at the bottom of the tube towards the inside of the dishwasher with another two wires going to it. I bypassed this one and re-ran and it heated up to 150 degrees and ran through the complete cycle. Bingo! This sensor/resistor is bad. I believe this controls the temp setting because when I re-ran again on the 130 degree setting, it still heated up to 150 degrees. The machine will run fine with this sensor bypassed and I will just be losing the 130 degree setting. Not a big deal for me, but I'll find a new sensor/resistor and replace.
Hope this helps someone else.