Hello, we just started getting intermittent P2BAA codes on our 2012 ML350 Bluetec. As usual, we always get check engine lights about 5 to 200 miles after getting a service at our local dealership. I looked up this code and it says "Oxides of Nitrogen Exceedance - Low Reagent Consumption."
So I am assuming this is related to the emissions systems. Has anyone gotten this code before and can tell me what was done to fix it?
I am going to top off the AddBlue, but it seems odd that you would get a check engine light before the car would display the "Please add addblue" message. But I thought I would give it a try just in case it made a difference.

Thank you,
Todd