Hello I see you have experienced with ml 350 ;
I was readying some of your post and suggested and try to find a answer for my problems. I don’t know if you can help but i decide to try and ask you . I have 2012 ml 350 blue and recently I’ve got check engine light. check the code and isP20BE Reductant heater B control circuit performance. I look on you tube and people wore posting that with that code I need to replace the pump and some of them are saying that I need to replace the def tank because the reductant heater may be inside the tank . I call few place’s and the tanks is 2100$ crazy of course become is MB . I did find a adblue pump from Canada for400$ refurbishment. Now I don’t know what to do . Any suggestions ??? Pleas help, I am so confused what I really need . Thank for your time and help . Elena T