# Strange DEF indicator issue



## MilTownSHO (Oct 9, 2013)

So the other evening I topped off my DEF tank (was showing at 36% or so) with VW ADBLU that I got for free. How did I get it free you ask... I work at VW/Mazda dealership in service.

Anyhow, filled her up, checked the display and it showed full.

Tonight while driving home I happened to check the display and it showed back at 36%. Now I know there is no way I used that much fluid in a few hundred miles.

I know DEF can freeze but I also know we have tank heaters. The car display showed -5 for the outside temperature on my hour and forty five minute ride home for reference.

I have never seen this behavior before even in similar weather. The only thing I can figure is different is that I used VW ADBLU.

Since the free maintenance is up I have been using the pump at Kwik Trip for DEF when it needs to be filled, so its not the first time the car has seen non GM DEF.

When I got home from my long drive I turned the car off and back on and it still showed 36% full. I would think it would have thawed out from that much time driving if the heater was running that whole time.

So either I cracked the tank somehow, the sensor is stuck, or the VW ADBLU I added did something strange.

Anyhow else experienced this or have any thoughts? It's going to stay cold for the next few days but I will check it in the morning and try to pull it in the shop tomorrow to warm up the fluid to see if it changes.


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## Snipesy (Dec 7, 2015)

I wouldn't worry about it. If its anything like other vehicles there are multiple sensors and none of them are really used for measuring the actual DEF level. Their only purpose is to insure the DEF is flowing nicely and is not diluted. Getting the actual level is an afterthought, but it will sure scream really loud when its empty.


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## spacedout (Dec 7, 2010)

DEF freezes at something like 12F, I'm sure this is the reason it wasn't reading accurately, because its frozen. Sure you have a tank heater but if your car has sat for hours no way even a 20 minute drive will thaw things fully.


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## Robby (Mar 1, 2013)

Several members reported no change or rather variable readouts shortly after filling the tank......then reported everything stabilized within a day or two.

I'd advise no worry untill a few days of operation have occured.

Rob


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## Tomko (Jun 1, 2013)

I saw this once in cold weather. Nothing to worry about.


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## boraz (Aug 29, 2013)

def is def

wait awhile the level will adjust with temp


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## Canadian Cruzer (Oct 27, 2014)

MilTownSHO said:


> So the other evening I topped off my DEF tank (was showing at 36% or so) with VW ADBLU that I got for free. How did I get it free you ask... I work at VW/Mazda dealership in service.
> 
> Anyhow, filled her up, checked the display and it showed full.
> 
> ...


See thread DEF tank


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## revjpeterson (Oct 2, 2013)

I see the 36% all the time in the frozen world that I live in. It usually shows up when the tank is frozen. I haven't had my tank apart yet, but if I understand the configuration right, I think that there is the main 4.5 gallon (or thereabouts) tank that is shaped like a spare tire, then a cylinder-shaped reservoir that inserts through the top of the tank, which has all of the electronics, including level sensor, heater, etc. I think that the heater only warms enough fluid to keep the level inside that reservoir high enough for the pump to be fed, thus the seemingly erratic readings in sub-12 degree weather. In my experience, the DEF only displays "36%" when the contents of the tank are frozen; otherwise, it only displays a numeric value at 35% or below. The rest of the time it just displays "OK"

In summary, I think what you are seeing is pretty much standard behavior for the low temps we are seeing, and it probably does not indicate a malfunction or a problem with non-GM DEF.


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## diesel (Jun 8, 2013)

It never consistently gets cold enough where I drive to see that issue. last year when we had the cold burst and it got down to -9F, I never thought to check the level. If I remember tomorrow morning I will check. Mine should be at least 1/2 full and it will be about 5F in the AM when I start it.


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## Cruzator (Dec 31, 2014)

Give it a week or two before having any concerns. Mine jumped around for 3 or 4 days after filling, and then finally said "ok".


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## MilTownSHO (Oct 9, 2013)

Thanks for the input, I wasn't super worried but just found it odd as I hadn't seen this behavior in colder weather than this.


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## theonlypheonix (Oct 8, 2015)

The DEF indicator sure is strange!! With 10,700 miles on the clock this is the first time I filled with 2.5 gal DEF, appeared full but gives 25% DIC indication
now. It all started at about 9200 miles with a 36% DIC indication, then it went out a day later, then 2 weeks later it came on again with a 25% indication.
For the last two weeks it stay on a 25% DIC indication until I filled her up last night and today with an additional 120 miles after the fill up its still on 25%?
I not sure, even with the cold temps, that the tank is frozen because the bottle of DEF came from the car trunk and the 2.5 gal bottle of added DEF fluid 
was not frozen !

Guess I'll see what happens in the next couple days when the temps warm up a little.


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## theonlypheonix (Oct 8, 2015)

Well now 15 days and 1700 mi later with the DEF DIC still showing 25% after a 2.5 gal fill up and two top offs, I was off to meet with the local service department on the DEF level problem. Simply they said all sensors reading correctly, tank was full ... it just got "confused" and needed a "manual reset through their scan tool! They did not even appear to be surprised over the problem as though they see it every day! 

Can you say software bug?? I'll have to see whether it is related to filing up around 25-30% and let it go down much lower before fill up next time?

Does anyone know whether the new Scan gauge II can do a manual reset on DEF Level and also a manual regen??


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## Canadian Cruzer (Oct 27, 2014)

theonlypheonix said:


> Well now 15 days and 1700 mi later with the DEF DIC still showing 25% after a 2.5 gal fill up and two top offs, I was off to meet with the local service department on the DEF level problem. Simple they said all sensors reading correctly, tank was full ... it just got confused and needed a manual reset thrugh their scan tool! They did not even appear to be surprised over the problem as though they see it every day!
> 
> Can you say software bug?? I'll have to see whether it is related to filing up around 25-30% and let it go down much lower before fill up next time?
> 
> Does anyone know whether the new Scan gauge II can do a manual reset on DEF Level and also a manual regen??


Same thing happened to me and my dealer also did the reset. Haven't put enough miles on to see if it will be the same next fill. BTW this happened to me in the summer so temp wasn't a factor.


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## diesel (Jun 8, 2013)

theonlypheonix said:


> Well now 15 days and 1700 mi later with the DEF DIC still showing 25% after a 2.5 gal fill up and two top offs, I was off to meet with the local service department on the DEF level problem. Simply they said all sensors reading correctly, tank was full ... it just got "confused" and needed a "manual reset through their scan tool! They did not even appear to be surprised over the problem as though they see it every day!
> 
> Can you say software bug?? I'll have to see whether it is related to filing up around 25-30% and let it go down much lower before fill up next time?
> 
> Does anyone know whether the new Scan gauge II can do a manual reset on DEF Level and also a manual regen??


Definitely no on the manual regen. As far as I know there is no way to do a manual regen available outside the dealer. 

Are you at DEF "OK" now? I have refilled around 25% and it fairly quickly went to "OK"


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## theonlypheonix (Oct 8, 2015)

yes, it is back to indicating DEF "OK", the shop was very clear that when adding DEF with a below full (OK) level indication the display should reset automatically within a couple minutes of starting the engine. They noted that DEF should be filled with the engine off, once full the cap needs to be replaced so the tank can be pressurized when the engine starts. After that it should only be minutes before the display updates to the "OK" state.

No definitive answer as to why it got "stuck" on 25% other then it must have been a "glitch" which can only be resolve with a manual scan tool reset. No charge to me other then my time/fuel to the dealer and back and I received an apology for the inconvenience.

I guess it'll be another 10K miles before I know whether its working properly or not, this would put it in the June time frame at the rate I drive. I do use a Stanadyne demulsifying fuel additive which is suppose to also reduce soot thereby reducing regen cycles so this may extend the range for DEF along with aiding in the other claimed fuel benefits of Cetane improvement, lubrication, anti-gel, cleaner, etc.


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## diesel (Jun 8, 2013)

theonlypheonix said:


> yes, it is back to indicating DEF "OK", the shop was very clear that when adding DEF with a below full (OK) level indication the display should reset automatically within a couple minutes of starting the engine. They noted that DEF should be filled with the engine off, once full the cap needs to be replaced so the tank can be pressurized when the engine starts. After that it should only be minutes before the display updates to the "OK" state.
> 
> No definitive answer as to why it got "stuck" on 25% other then it must have been a "glitch" which can only be resolve with a manual scan tool reset. No charge to me other then my time/fuel to the dealer and back and I received an apology for the inconvenience.
> 
> I guess it'll be another 10K miles before I know whether its working properly or not, this would put it in the June time frame at the rate I drive. I do use a Stanadyne demulsifying fuel additive which is suppose to also reduce soot thereby reducing regen cycles so this may extend the range for DEF along with aiding in the other claimed fuel benefits of Cetane improvement, lubrication, anti-gel, cleaner, etc.


Keep us posted


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## theonlypheonix (Oct 8, 2015)

Well I'm now another 12K miles down the road on the clock and have another 25% DEF indication. This time things are a little different. Before the dealer fixed the problem the first time I was able to get a reset prompt for the DEF level. Now after they fix the problem the DEF display no longer display a prompt to reset the display. What happens now is after the fluid is topped off, CAP put back on the tank and engine started the display will reset within minutes or a few miles of driving now, all automatic no driver intervention required. Seems this suggests there was an initial software bug and the unit was reprogrammed so now the driver does not have to manually reset it.

But in any case all appears well after topping it off now, the second time at 24K miles.


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## diesel (Jun 8, 2013)

theonlypheonix said:


> Well I'm now another 12K miles down the road on the clock and have another 25% DEF indication. This time things are a little different. Before the dealer fixed the problem the first time I was able to get a reset prompt for the DEF level. Now after they fix the problem the DEF display no longer display a prompt to reset the display. What happens now is after the fluid is topped off, CAP put back on the tank and engine started the display will reset within minutes or a few miles of driving now, all automatic no driver intervention required. Seems this suggests there was an initial software bug and the unit was reprogrammed so now the driver does not have to manually reset it.
> 
> But in any case all appears well after topping it off now, the second time at 24K miles.


interesting. I never had an option to reset on my car.


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