CEL and DEF overflowing

My 2010 has set a CEL which has come on and off a few times recently,
It has now come on solid and I find the DEF fluid tank filler is overflowing.

Any thing I can try before driving 2 1/2 hours to servicing dealership? (Freightliner) it is still under power train warranty.

Did you pull the CEL code? If you don't have a scanner, any autoparts store should do it for free.

Is the DEF tank full? Take cap off and verify. I just filled mine the other day and just realized there is some type of vent tube from the reservoir back up to the filling snout/catch. That explains why in the past i've seen white crystal around the snout even though I have never spilled any while filling.

I'm pretty sure there is a drain tube clipped to the side of the tank underneath. In case you want to drain some out. But I am also curious to know why it is overflowing.

boatmangc said:

My 2010 has set a CEL which has come on and off a few times recently,
It has now come on solid and I find the DEF fluid tank filler is overflowing.

Any thing I can try before driving 2 1/2 hours to servicing dealership? (Freightliner) it is still under power train warranty.

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In short there is not a lot you can do.
The Adblue system is not generally on an OBD2 listing so generic scanners won't generally show up a related fault .

I had one 'similar the other day on 2011 model.
The Def pump outlet stub had sheered off hence the leak.
The def injector was clogged up so I think developed pressure had done it in!
Somewhere along the failure pattern the pump must have caused it to back feed or pressurize the tank and the owner was complaining of expulsion of fluid before the whole thing took a dump.
Having dropped the DEF tank down we found the outlet pressure stub broken so that meant a new pump @ $770.
We replaced the blocked up the DEF injector assy at $220 and it seems to work fine after that with scan program/adaption and test.
Bill was about $1500m by the time we were finished !
Maybe yours is the same malady and let me know!
Curious
Dennis

Will do, I will make an appointment at the Freightliner dealership, I fortunately still have warranty till September.

It's leaking a lot! I had a client call me and tell me I left a trail going down the road after I repaired his outboard motor.

I just had a somewhat similar issue, my CEL light comes on not the add DEF light. I have no idea what the code on my AutoEnginuity scanner ment. It was a DEF sensor plausibility error. So I bring it to the stealership they tell me no CEL light was on and they added 11 liters of def fluid in all is fine pay the bill $200.00 I don't want to pay to have someone add fluid, and I want to know why the add def light did not come on. I have 50k miles on the 2011 Sprinter, so I know how it should work, the light comes on you add fluid the light goes off. I hope someone has some suggestions.

Kid347 said:

I just had a somewhat similar issue, my CEL light comes on not the add DEF light. I have no idea what the code on my AutoEnginuity scanner ment. It was a DEF sensor plausibility error. So I bring it to the stealership they tell me no CEL light was on and they added 11 liters of def fluid in all is fine pay the bill $200.00 I don't want to pay to have someone add fluid, and I want to know why the add def light did not come on. I have 50k miles on the 2011 Sprinter, so I know how it should work, the light comes on you add fluid the light goes off. I hope someone has some suggestions.

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Well first I am not sure your AE scanner has the ability to fully interrogate the system(s)
I mention SYSTEMS because there is the PCM and the Adblue module.

Since these two modules have intercommunication a system malfunction will throw a CEL the Adblue symbol might not be illuminated .
Now using your scanner I am going to presume you used it ONLY as a code reader. Hence you obtained a plausibility error fault/code which you had difficulty in interpreting .
If you have the ability on the machine to read data from the Adblue module and its system, then it would have displayed a string of information on heaters , pressure, level status and whether each sensor is "wet" to mention a few!
Of course it begs the question if you were able to get live data could you interpret that and effectively determine what was causing the CEL to come on in the first place.
Usually it takes a bit of technical training and servicing experience as a shop mechanic/tech to quickly pinpoint the problem area.
If you are in the trade have you been on any training courses to fully understand how the system works and interacts together?

Since your testimony doesn't include what the the dealer did to eradicate the CEL I can only assume it dropped out of adaption or had communication error which by the way is not unusual. They (dealer) merely added fluid which I would have done, noted then cleared the code and looked at the relevant live data coming out of the systems. Then maybe did a re-adaption or re-flash as appropriate ! Who knows!
Satisfied with the result of full preparation returned it to you for the time it took to fix it/make it work to spec.
The $200 bill isn't outrageous and is commensurate with auto repair/service industry norms.
Hope that goes somewhere in explaining what has happened.
Dennis

Take a look underneath the van and see if you can see the leak. probably from the injection line . if it is obvious then, unplug the injection valve on the exhaust (just unplug it) secure the connector so it does not get melted by the exhaust. doing this will shut down the tank system from building pressure, but it will cause other codes. get the van to the nearest repair center and get it fixed . be sure to tell the adviser that the valve is unplugged by you so that the fluid would not spill all over the ground.

Carl

sprintguy said:

Take a look underneath the van and see if you can see the leak. probably from the injection line . if it is obvious then, unplug the injection valve on the exhaust (just unplug it) secure the connector so it does not get melted by the exhaust. doing this will shut down the tank system from building pressure, but it will cause other codes. get the van to the nearest repair center and get it fixed . be sure to tell the adviser that the valve is unplugged by you so that the fluid would not spill all over the ground.

Carl

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It appears to be coming out of the filler cap