I brought a 2009 GL320 BlueTec from a local MB dealer a year ago. Done few small fixes on my own since, expensive parts but nothing major. Since the last full tank of DefBlue, maybe 2000 miles ago, I'm now getting a CEL with code P203D ("the AdBlue fill level sensor has a short circuit to positive"). I can clear it, but it will just come back about a restart or two. I have been reading alot about this code. I saw a lot of reference to software update. How can I think if my vehicle need the software update, beside just taking it to the dealer? Is there a way to find out what "version" is in my SUV, what version is available, and is that something that can DIY?

Thanks.

 

Take truck to dealer. 30 minutes to check for updates and update scr module if needed. About $75. There is an update that addresses a false positive p203d as well as other scr- related false- positives. If error comes back you need to replace heater element/ level sensor assembly. About $1800- 2000 done at the dealer. Good luck