Really long story, but my seat in my W166 was shaking side to side when I go around corners, so I took it out to see if there was a bolt that needed to be tightened. When taking it out. I moved the seat all the way forward to get to the rear two bolts and then all of the way back to get to the front two bolts. I tightened up some nuts and started to put it back. I put in the front two bolts and then connected the electronic seats. Then the electronic seats won't work making it impossible to get to the rear bolts. There is a message on my car saying "Front Left Malfunction Service Required". Well..... I reinstalled the seat with the rear driver side bolt in place thinking there was a sensor there as that is the side with the seat belt (didn't see one, but it was the only thing I can think of). Well, I don't know if that is what fixed it or reseating the electric connectors (I ensured they were in there in the first place but who knows?). Now, the seat is firmly bolted into place, the electric seats work but I still have the warning saying there is a problem. Is that something I can reset? If so, how? Will it go away?

 

I can't answer your question, but did you cure the shaking?

 

Almost! It was gone for a day or two, but it is back. It isn't anywhere near as bad as it was, but it does it once in a while. There are only two bolts on the front that you can tighten; nothing in the back. If you have this problem, you might look at the bolts in the front and that is it. Don't bother taking out the seats as it didn't provide access to anything. If you take the seat out without disconnecting the battery you will get a fault code for the airbag in the seat not working. This isn't something you can fix and have to go to the dealership to fix. Lesson learned.... Don't disconnect the wiring for the seat unless you really have to!