mikemargolis

Hello all,

I have a 2011 E-350 Bluetec diesel, OM-642 engine, with 125,000 well maintained miles, about 200k km.

5000 miles ago I had the oil changed, and filled the adblue tank. I have the work done at an indy, and always fill the DEF myself right after the oil change.

Last week, I got a warning that I had only 16 starts left, and that I needed to fill the DEF tank. Wondering if I had maybe forgotten to fill the DEF at the 120,000 mile oil change, I drove to Wal-mart, bought three 2.5 gallon DEF boxes, and began to fill in their parking lot. (I have a 1/2 gallon bottle I bought from M-B, and cut the bottom off, and use it as a funnel).

It took a tiny bit less than ONE 2.5 gallon jug, pretty much exactly what I thought it'd take after 5000 miles. I went back inside and returned the other two jugs.

So, here's the $64,000 question (well, really I bet it's a $1000 question, because everything that goes wrong on this car costs $1000):

What would make the 16 start sensor go off when there's still 2/3 of a tank in the DEF tank?

Thanks in advance....

ItalianJoe1

Bad sensor in the tank is usually the case.

mikemargolis

And can that be repaired or do I have to replace the tank? (Which I have done once due to a bad heater, for more than $1000)

kajtek1

With W212 there is not much DIY anymore.
Any sensor replacement require SCN coding. Start with reading what error you have.
FYI there is Belarusian ebay seller who sells OBD plugs, that will clear the count.
But sooner or later you will have to address the issue.

mikemargolis

By having the sensor replaced or by having the entire $1500 tank replaced?

(or just filling it every 5000 miles?

kajtek1

I heard much higher estimates for new tank.
Either way, 5000 miles refills are still a bargain.

many birds

Could also be a bad NOx sensor, also $1000+ expense--that's what happened on mine. The sensors themselves are expensive and then they need to be coded to the ECU.

kajtek1

For my 250BT I bought NOx sensor for $250 at Husker and took it to dealer, what cost me another $250 (maybe slightly higher with junk fees).
350BT has the sensor costing $100 higher for some reasons.

jkaetz

Currently dealing with this on a ML350 Bluetec. Both my scanner and the instrument cluster claim that the tank is full. It has one more clue though in that there was a CEL 106100 claiming that the upper limit value for long-term adaptation of the SCR was exceeded. I can clear the code but it comes back on the next restart. With only 16 starts, you have very few days to investigate without a secondary vehicle. Will let you know what our issue is. There is a long term solution but it is for off road use only. IMO if a vehicle is going to self disable itself for an emissions fault, that should probably be disclosed to the buyers up front. We were under the impression that only an empty DEF tank would cause it to count down starts and that we would get more than 16 starts to address the issue.

jkaetz

Had an independent look at it and while they thought they could reset the counter they could not. The must have gotten something to reset though as they did get the check engine codes to stay gone. On the way to the local MB dealer with 4 start remaining the system beeped, jumped to 16 starts, and added the check additive message. The dealer stated that the only code active was the one for the start countdown. They reset it, tested the adblue system and everything reported ok. Charged for 1 hour.

I also requested that they check and update the CDI and SCR modules if there were any updates found. They updated both. 30 or so miles later now with no codes and no countdown.