Have Mercedes Questions? Ask a Mechanic for Answers ASAP
Hi my name is ***** ***** I will be happy to help with this today.I need a little more info to assist better.
Has your vehicle had the recall done for the software update at all by a Mercedes dealer?
Let me know so we can continue,thanks Pete.
O.k.,there is an issue with the heating element operation for the tank itself and there is updated software for the Selective Catalytic Reduction control unit SCR on almost all of these models with the 642 engine code U42.The recall number I see is(###) ###-####If this was not checked and done this should be done as this corrects false warnings for the ad blue system.This recall is covered in cost by Mercedes.
If this is checked and found out to be o.k. I have seen the SCR with an internal electrical fault that will cause false warnings like this as well as wiring damage leading from the sensors at the tank.I would then have the wiring checked to make sure this is o.k. and if found o.k. I suspect the SCR may need replaced and programmed.
If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.Thanks Pete.
Your welcome.Let me know if you need anything else and feel free to rate my help here.