So I purchased my 2012 R350 in August with a check engine light on (MB Dealer auction with 68,000 kms) When I got it my dealer told me it was the buletec heater. I changed that and was good for about 3 month, then another check engine light. This time is was P20B8 and was told by Mercedes that it was now the bluetec pump. So I had it changed (not from MB) and 1 month later same code? What could this be? I am stumped and so is the guy who replaced both Heater and pump. Any suggestions.
Thanks

 

Anyone?

 

Sorry to bump and old thread, but the code came back! I have changed the bluetec heather and pump, so what is left!!! So frustrating that I can't fix this problem. Any suggestions?
Thanks

 

Hey, did you ever get this figured out? My 2012 R350 BT is doing the same thing all of the sudden. The AdBlue warning is on; countdown of starts initiated. I took it to the dealership today, and they looked like a deer in the headlights! They made an appointment for later, because "this is never simple". Yikes...get me out of this Mercedes!

 

Nope, light went off and never came back! It has to be an electrical glitch. Had to changr my front air strut since that started to leak!

 

 

 

 

Have you changed the ad blue level sensor? and did you use a MB heating element when you changed the heater in the tank?
I replaced my heater level sensor and pump. I used an XEmodex heating element system and it has worked flawlessly. I did it myself at my Independant repair shop I own and operate and it took about 3hrs total including answering the telephone 14 fricking times.......

 

I dont know. I will ask the mechanic who performed the job. Funny enough the light went off this morning, so I will wait until ot comes back on. Thats whats making me think it might be an electrical issue.