Low DEF warning light on 3L turbodiesel Solera

[BANDYS]

Has anyone experienced this warning light coming on? I topped up the DEF before leaving on the last trip, and it came on after 100km. I'm now in the countdown stage for the number of starts I have before the engine goes into limp mode. I topped up the tank again when I got home, but the light is still on

[Ford Idaho]

Bad sensor or the ECM is off.

[DDC]

System needs to be reset, can you get into the system on them? If it is the MB system I believe they need to do it.

[devilsquid]

We had that light come on during our first trip out. Apparently the dealer that sold us our Solera didn't top off the tank. After I found out what that light meant and found a place to buy the DEF we filled the tank. The light stayed on even after I filled the tank. Got home, light still on, called our MB dealer and made an appointment. The light went off when I was about 10 minutes away from the dealer. Took it in anyway and they could not find a thing wrong with the system. I now take extra DEF with me any time we go out and hope that light doesn't come on again. Limp mode is no fun (previous Class B).

[JLeising]

On our 2012 Solera I found after re-filling the DEF, I had to wait with the ignition on (all indicator lights lit) but the engine NOT started until the indicators turned off to re-set the DEF indicator.
Just shutting down and restarting did not reset the indicator.

[Mikegjax]

I top mine off before each trip and won't wait for the light to come on.
Normally after returning from a trip I wash the RV and top off any fluids. After second wash I wax. May seem like overkill for the wax, but want to keep it in good shape. Did the first oil change at 8500 miles because I new and did exceed 10,000 this last trip. resetting the oil maintenance light was easy.

[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.

[hkreck]

I have had the DEF light come on in out of the way Texas, continued to drive until I found a gas station that carried DEF fluid. After filling it up started the engine and the light came on but after a few minutes it did reset like it's suppose to. If yours doesn't reset I'd have to say take it to an MB dealer. As far as I know there's no reset that you can do yourself.

[devilsquid]

In my case we were coming down the pass on I-90 west of Seattle when the light came on. Stopped at a truck stop filled the DEF tank, turned the key, waited for the idiot lights to go out (all did except the DEF indicator), decided to eat lunch, then drove home with the light on (approx. 200 miles). That same dealer in Bellingham didn't find anything wrong...I too don't really trust that there is nothing wrong with this system. If/when it happens again I hope I can get our Solera to a dealer before that light goes out again.

[Still Kickin]

Originally Posted by JLeising

On our 2012 Solera I found after re-filling the DEF, I had to wait with the ignition on (all indicator lights lit) but the engine NOT started until the indicators turned off to re-set the DEF indicator.
Just shutting down and restarting did not reset the indicator.

X2. That procedure cycled the def light off. As I understand it there are two computers that need to talk to each other to allow the program to reset the add def warning light.

[Still Kickin]

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.