P203E Code, DEF Level Sensor Failed/Erratic

[Longhorn1500]

Okay, I'm confused. I got the P203E code last week along with a CEL, "Reductant Level Sensor 1 Circuit Intermittent."
Everything that I have read states that this code has three causes, 1) Over filling the DEF tank, 2) DEF frozen in the tank, and 3) DEF crystals obscuring the DEF level sensor. I live in western Washington State, the lowest temperature so far this year is 37F, so I expect the DEF has not frozen (I think DEF freezes at 12F (?)).

Okay, at the time I got the CEL, my DEF gauge showed just under half full, and my iDash indicated a DEF level of 46%. That afternoon I added a 2.5 gallon jug of DEF, the gauge showed just under full and the iDash level indicated 75% full.

It seems like my DEF level sensor is working fine. Yesterday I attempted to clear the CEL code with my iDash but it would not clear. After reading articles and watching u tube online, I found that you can clear those types of codes by cycling the start button (or key) 5 or so times (foot off the brake pedal, so not starting the motor). I tried that and was able clear the code, and the CEL turned off (yay!!).

Here's where I'm confused (more than I already was), the countdown to doom message is still there (Limited to 5 mph in 150 miles (now 61 miles) Service DEF system See dealer).

I have started and driven the truck four times, latest was today, since I was able to clear the code. How do I get that message to clear too??

I do have an appointment at the dealership on 3 January (the earliest they could get me in).

Things like this happen and it makes me want to put my truck on a diet...

 

[GTyankee]

I seem to recall something about the DEF Tank
i do not remember what the code was.

There is a plate, i think at the bottom of the DEF Tank.

I will try to find the video, even though it may not be your Rams issue ..

 

[GTyankee]

You are going to need to save these, Print it out, if possible

There is a Technical Service Bulletin out on this same issue

https://static.nhtsa.gov/odi/tsbs/2023/MC-10236935-9999.pdf

&

https://static.nhtsa.gov/odi/tsbs/2021/MC-10194039-9999.pdf

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watch this video, if it works, Great

Ram Cummins DEF Debacle: This Tiny Expensive Part Broke My New Diesel Truck - Can I Fix It Myself?

( https://www.allTFL.com ) Check out our new spot to find ALL our TFLstudios content, from news to videos and our podcasts! Ram Cummins DEF Debacle: This Tin...

www.youtube.com

I see that the video did show the plate that i mentioned above,
Its at the bottom of the DEF Tank
But that is a different issue

 

[Longhorn1500]

Thank you @GTyankee I have seen the 2021 TSB, but not the 2023 one. I suspect I have the issue outlined in that one, where the solution is:

"This bulletin involves replacing the urea delivery module and grade vent valve and updating the Dosing Control Unit (DCU) software."

It is possible that I overfilled the DEF tank back in May, it did not take quite the whole 2.5 gallons (the last time I added DEF until last week), I don't know why it would take so long for the issue to show up, as stated above, it was down to 46% when I got the messages.

Oh well, I'm going to print that TSB and take it with me when I see the dealer at the beginning of January.

Thank you again!!

 

[Longhorn1500]

Well, I had my dealer visit yesterday. The countdown continued. When I left home it was at 37 miles until the 5 mph derate. By the time I got to the dealer it was at about 15 miles. Was getting the messages the whole trip. Well, guess what? No message when they started the truck (!!). They took it for a short test drive, no messages. They took it for a longer test drive, probably almost 40 miles, no messages. Fortunately for me, they did not charge me. So, I guess we'll see if the issue comes back. One thing I am not going to do is fill the DEF tank all the way up...