DEF/SCR system failure , need some info

[-gtsm-]

Hello , I am at sea working in the Gulf of Mexico . My wife drives a 2017 3500 DRW megacab which currently has just over 100,000miles . The DEF gauge suddenly dropped from 1/4 tank to empty and triggerred the limp mode warning in x amount of miles... so she pulled over at the next oportunity and put 5 gallons of DEF in it . This did not register on the gauge ... it still reads empty . The CEL came on and she drove it home . She emailed me so I started researching on line to see if I could get an idea of common failure modes ... I had her take it to Autozone to scan the codes and got P203B and P203F . They cleared the codes afterward and she drove home . The CEL came back up but not the warning of impending limp mode . Now I know what the codes mean P203F is LOW reluctant (DEF) and P203B is reluctant sensor range/performance . So I'm assuming the two codes together mean that the sender failed somehow and the truck thinks the tank is empty .
I was very surprised to find that there is very little discussion on TDR about this issue (typing in the codes in search resulted in zero results)that I could find other than "take it to the dealer and get bent over to the tune of 2100 bucks for a new tank assembly . I found another post where clearing the codes helped but in our case , no. I hated to sell my 2006 5.9 and get a new truck with the emission junk for this very reason but , here I am. If anyone has thoughts on this I'm all ears , I'm going to have a friend go over to the house tomorrow and try to clean the electrical connection going to the sender (if it's accessable) because the wife did drive through high water recently . Curious as to what's involved with deleting the SCR system also ... can't seem to find any info on that either. Internet out here is very slow so it's pretty painful trying to research this.
Thanks , Rich

 

[TFucili]

I think Motor City Mechanic did a few videos of DEF system cleaning and troubleshooting.

 

[Ozymandias]

Emissions warranty is not?

 

[DonFitzwater]

Rich, tell Momma to trade that puppy off and get a new one with 0% interest! You’ll most likely need a new def tank module.

 

[-gtsm-]

I will try to watch the videos ... if I can , bandwidth is sketchy .
Pretty sure it's out of warranty ... Somebody correct me if I'm wrong.
Considered a trade when I saw the 0% deals ... checked with a dealer who had a similar 2020 model on the lot and he offered me 27,400 for trade ... my trucks a laramie longhorn with all the bells and whistles ... sticker was 74000 bucks... uuumm no! I didn't bother to even shop around . My wife put's lot's of miles on her trucks , this is her third cummins diesel ... gonna keep this one a while, like the others. Just need to figure out the best way to deal with this issue while I'm away from home .

 

[sag2]

The level sending unit is with the pump assembly. It is $1800 MSRP. Tank does not include pump or level unit and is $995 MSRP.

 

[TFucili]

Holy smokes, that's outrageous.

 

[gsbrockman]

All I can interject is to source a used tank assembly (complete) from a boneyard if you don’t like the price of a new one.....

 

[Wiredawg]

I know it's tough with the Missus by herself... do you have anyone who could disconnect the batteries for about 20 minutes and reconnect them? Not say this isn't a hard failure, but the truck is a computer network and sometime a cold restart (reboot) could possibly help.

Please let us know how this progresses.

Cheers, Ron

 

[-gtsm-]

A friend of mine is there now.. he dropped tank and disconnected all electrical connections and cleaned them (one going to pump , and two going to the DCU ) he just got it all back together and restarted truck ... didn't work . I will have him disconnect batteries and drink a beer ... wish us luck.

 

[Wiredawg]

I read somewhere someone had this problem, but it wasn't a hardware issue... after refilling from near empty, for some reason, computer didn't recognize DEF was full... truck didnt go into limp mode though and took a few start cycles for system to sync up and display properly.

On the battery disconnect, I disconnect both pos and neg from both batteries, then short the pos and negative battery cables together before reconnecting.

I'll still see if I can find it and let you know.

Cheers, Ron

 

[-gtsm-]

Anybody have info on the delete process? If it's easy and reversible ... maybe we can fool the truck until I get home and can make the proper repairs .
I can't believe there's not more discussion on it ... This is not the TDR I remember .

 

[-gtsm-]

thanks wiredawg , was it this thread ? https://www.turbodieselregister.com/threads/def-gauge-inaccurate.268940/

 

[nukegm]

Anybody have info on the delete process? If it's easy and reversible ... maybe we can fool the truck until I get home and can make the proper repairs .
I can't believe there's not more discussion on it ... This is not the TDR I remember .

comrade - if you want to go to a forum where more people delete their trucks, try " ramforum.com "

in my opinion, this forum is more leaning to people who do not fiddle with their 50,000 plus dollar vehicles.

plus, anymore, if you get caught tampering with the emissions its a big deal. not like it was in 2000.

good luck with your def issue. hope your buddy has more than one beer. cheers.

 

[TFucili]

This is not your issue, but gives an idea of the setup, and that the gauge sender works by sonar.

 

[TFucili]

If it's the unit, and you don't go used, Summit does show an aftermarket unit from Spectra for under $800.

 

[Wiredawg]

thanks wiredawg , was it this thread ? https://www.turbodieselregister.com/threads/def-gauge-inaccurate.268940/

I think it may have been the article. Deleting is getting harder as EPA is busting manufacturers and dealers for selling programmers and hardware to modify, defeat, remove, or otherwise alter stock function.

Did your friend find any crystalization in the tank or in any of the hardware? At the injector nozzle? Has the truck actually gone into limp mode? I know pushing it is dicey.

The DEF level appears integrated into the pump. Heres som pics hope it helps,

And pump plug pin out

Maybe focus on the DEF tank level circuit to see if an issue.

Cheers, Ron

 

[-gtsm-]

Thanks for all the info , My buddy disconnected the batteries and that was a no go . He sent me some good pictures of the components , so I can at least price shop those ... I'm only assuming at this point that its the sender/pump module . It looks replaceable so I have no idea why Chrysler would replace the whole tank .
20 yrs ago when I joined TDR this place was all about doing your own repairs / maintenance and BOMBing our trucks " BOMB" = "better off modified baby"
hell the motto was " I am my own warranty station" .
I had to quarantine for two weeks prior to boarding the ship I'm on and I don't expect to get off of here until July so... I may end up having to take it to the dealer ... Don't wan't my Ol Lady stuck in limp mode while dragging horses across state lines. It's her Daily driver as well.

 

[-gtsm-]

For what it's worth , I have an HP tuners setup at the house that I could use to possibly troubleshoot the issue ... but the learning curve on it is too steep for me to try to explain over email to my buddy that went over to check out the connections for me today . I used it to retune a 2014 Ram 1500 Hemi that had a wiped cam due to an MDS failure ... I replaced the cam with a comp cam unit , locked out the phaser , added hellcat lifters , and deleted the MDS . But that took me days to figure the programmer software and I had help developing the tune. **** like this always happens when I'm working... hell I was stuck home for a month not working in March.

 

[Wiredawg]

Check this out:
https://docs.google.com/viewerng/viewer?url=https://static.oemdtc.com/TSB/25-001-15A.pdf&hl=en_US

A TSB that may be applicable.

Cheers, Ron