Poor DEF quality no check engine light

[FnG92]

2014 t800 isx15 2350. Dash lit up with message piir def quality and gave me a 2 hour timer for derate. I pulled over and topped off my def tank with less than a full spare def box I carry on the truck. My def gage is full with a red light lit up. Any helpful suggestions on what to do would be very appreciated!

[Rawze]

It could be poor quality def fluid.. which case, the tank needs to be flushed and new def fluid put in .. however ...

The def quality sensors are also notorious for going bad. - The problem is when they do, there are no replacements to be found anywhere.. as they have been known to often be on back-order for 6 months to a year+.


(for people with a warranty on their truck and emissions systems still)...
The problem is so bad that cummins themselves has a program update/patch to allow someone to drive if it is only that one bad sensor and the CEL light staying on, without it shutting the whole truck down. So if a person is near a stelaers$it and it is still has an emissions system warranty on the truck that is active, then that is one possible place you could go to maybe have it dealt with. The trouble is that someone then has to try not to get ripped off for some bogus shop fees or other things the stealers$it might want to claim, essentially ripping you off in the process for that ehemm .. so-called ... "free" repair.

(for people with no more truck warranty)...
Otherwise if there is no warranty and a replacement sensor is nowhere to be found ... then you might very well be looking at having the programming that you already have, 'patched' so that it does not shut down for this problem while waiting for a new sensor the next year and a half if it is one of those parts on the endangered species list. Some of those DQS sensors are sometimes fetching more than $3,000+ for just a used one out of a junk yard, due to the over-demand. Copying the program out of the ecm and e-mailing it to one of the recommended people on here, or myself, it can be patch to allow the truck not to shut down, or whatever other course of action, etc.

[FnG92]

First and foremost, I fucking love you man.
After driving for 60 minutes, I got a reading on dash, %25 derate and then it disappeared 5 minutes later. My def level has gone down and truck is performing as usual. I do know that the level sensor on my def tank stops showing at 1/2 and I always just top it up at every fillup, this is one of the many reasons I keep bottled def. I happened to leave my tank uncapped spilling def out of the tank fill port on my truck. This may have purged some bad deff by accident. I have never had this message come up when I first found out that my level sensor is bad, so I'm hopeful that it was just bad DEF that I diluted with bottled def and then purged by accidently leaving my tank uncapped.

I started to lose my mind because my truck asked for a manual regen (switch on dash) 5 days ago.

Thank you for everything that you do rawze, you're a good guy. I try to be in the habit of donating every time I ask a question, however I'll need to wait a bit before I can do my part to keep this knowledge that has helped me, available at no cost for the other owner operators that come here for assistance!

I'm my trucks warranty lol

[RollinCoal]

Bottled def is ok but you cant let it sit, its water based and will evaporate and screw up the concentration,
If you need the cummins def level fix send me your esn Ill see if its available for your truck
But it really helps to keep the def tanks full, As the level drops the def will crystalize in the tank and can cause the level sensor to get stuck and or not read correctly

[Nilao]

Unfortunately you can't rely on bulk DEF either. So many times I have seen where a truck stop has shut down their DEF pumps due to contamination. One major chain had to pay to flush hundreds of trucks cause their DEF tanks got rainwater in them and diluted the urea content.

[RollinCoal]

yeah thats not good

[FnG92]

This community is the greatest. I could not have made it for as long as I have without the information I get from here. I have not ran into this problem again. I think it was actual bad poor def quality. I know what I need to do if I run into this problem again. I don't feel helpless, thank you everyone!!

[DVT873]

FWIW DEF tank heater valves are part of the problem with the quality level sensors. The valves stick open. This can raise the DEF fluid to as high as coolant temp. The high heat damages the sensors. https://rawze.com/forums/showthread.php?tid=5263 . I think I saw more about that on this site but can't find it at the moment.

[Lonestar10]

Good luck on def with union Pacific crooks trying to extort the flying j crooks on rail shipments probably due to buffet owning both flying j and bnsf