Hello guys, i’m a new member of this forum and i’ve been following the discussions on the GLK for quite some time now. Just to introduce myself, I live in Tirana, Albania and for two months now i’m owner of a Canada imported 2014 GLK 250 bluetec. A few days ago, i was going for a long journey with my family and while driving i got a CEL. Not knowing what to do, and not having an ODB|| scanner (yet), i found a indy car shop on the road who diagnosed my car with a P204FFB code, but had no time to deal with it (was already full of customers and leaving the car there was not an option for me). So off i drove and after 20 km i got 10 starts left. To make the story short, i arrived home with 5 starts left. The next day i went to another mercedes service shop and they diagnosed my car via Xentry and told me that the NOx sensors were the culprit. They told me that both sensor were very expensive to change and they offered to disable the adblue system altogether. They also said that the modification is reversible whenever I choose to do so. So they disabled the adblue system via rewriting the ECU i guess and unplugging the controller in the trunk. I was there the whole time and no parts were removed from the car, with the exception of the ECU.
I did not actually witness them rewriting the ecu, i just saw them remove it, take it someplace nearby and returned it after 20-30 minutes. Now car works fine, no cel or other messages so far. As for the consumption i guess is too early to tell. My question for you guys are:

Is this the correct way of disabling the scr?

Can someone please confirm that the P204FFB code is indeed related to the NOx sensors?

Can someone suggest me an affordable decent odb2 scanner?

Thank you in advance

 

I would say as long as you don't have emissions inspections in your country which require the ECU to be scanned to see whether it's operating on "approved" MB software, I wouldn't worry about it.

They did you a favor.

As for OBD2 scan tools, there are many available but it varies on your location/market. I would suggest contacting the shop that just did the repair and see what they recommend as a good consumer (ie, non-professional) tool.

 

Good advice from Andreigbs, many scanners out there. I'm using Icarsoft II for MB and happy with it. BTW my 250 is also deleted and trouble free for two years now..