When you mention you checked the impeller is free and clear, are you speaking of the circulation pump impeller or the drain pump impeller?
At a very basic level, a dishwasher does 3 things- fills with water, sprays it around, drains it out. On the Miele when you start a cycle, it will run the drain pump first for about 30 seconds or so to make sure there is no dirty old cold water in the unit. It wants to start with fresh hot water. It then will fill with fresh hot water. After that, it will engage the circulation pump and begin the wash cycle, spraying the dishes.
The intake/drain light is a generic fault code light. It can come on for many different reasons. The most common is that the circulation pump is stuck.
The unit will drain then fill then do nothing as it can't spin the circ pump to spray the water.
Miele makes a special tool for this, but you can make a substitute very easily out of an old kitchen fork or similar.
If you remove the metal screen under the wash arm, down in the back of the sump you will see a rectangular hole.
If you were able to see in this hole, it is where the impeller for the circulation pump is located. The Miele tool is a simple U shaped fork that you stick in this hole to engage the impeller and simply twist it back and forth in a clockwise-anticlockwise motion to unstick it and allow it to spin freely.
I have done all that, this is not the firts time I have this problem; the last time the technician had to reset the electronics somehow to fix it and said at the time that M.
Mieles were very finicky
I am hoping that i don't have to call a technician and spend another $100 on something I may be able to do myself
Actually, they are quite robust. If you are 100% sure that the circulation pump is moving freely, then I would advise you to call Miele technical support. Unfortunately, something such as a faulty heater pressure switch or a bad water flow meter, or even the water inlet valve/hose assembly can cause the same light to come on. All of which will require specialized parts and a person familiar and comfortable enough to remove the unit from the wall and take it apart to repair.
I was afraid of that. Thanks.