Originally Posted by 3886john
We have a 2013R and just love it, but let me tell you what a nightmare that DEF light has been. Usually starts with the check engine light but not always. Last disaster was July 4th headed from Wisconsin to Idaho 20 miles from home light comes on. Nobody is open of course and none, I repeat none of my Mercedes phone numbers get answered. Get to Idaho and down to 8 starts then up to Spokane Monday morning, July 7th, to the 4th dealer that this unit has been to, 2 of which it has been to 4 different times each. It is another time I went some where I did not want to go and spent another 5 hours standing around some where I did not want to be. They (Spokane MB) tell me it was a software problem and they have fixed it. I have heard that before, get the managers name and phone number, saves time at the next dealer when the new mechanic can talk to the last one. Sure enough 3 hours down the road it's on again. Next morning we are standing at the door of the Bellingham, WA MB dealer (the 5Th Mercedes dealership this thing has been to) waiting for the shop to open. Direct to the manager's office and I quote "Sir I know this is not your fault and you wish it did not happen but we need to get Franz, Carl or who ever the head German is on the phone because I am not going to let Mercedes spoil another vacation for me. Wisconsin has a lemon law and I am ready to rent a motorhome and leave this thing right where it is parked." I now have my 3rd and 4th Nox-sensor's on it and it did finished the trip. But I don't trust it and I am not sure I ever will.
May I suggest, when your back at your home, contact MB regional representative with all your history and, request that both computers be replaced. I say this because a friend of mine did that exact same thing. Except in his case one of the MB dealers went to bat for him, and took it upon themselves to go direct to the MB regional rep for approval. He has had no problem since both computers were replaced. Good luck.