Dreaded DEF system issue... you're screwed in xxx miles

[bfs673]

Had the above warning come on yesterday while traveling for work. I was roughly 100 miles from home when this happened, so I turned around and immediately went home.
I had put 2.5 gallons of DEF in the tank the evening before, but noticed the gauge didn't reflect the addition. Was at 1/4 tank, so should've moved to 3/4.

Just finished up with the dealer who simply reprogrammed the ECM per a TSB (TSB number was not specified) referencing P203e code (reluctant level sensor).
The code makes sense, but the TSB leaves me perplexed.

I presume they are referencing TSB 18-034-21 which lists the following likely causes:
Scenario #1 - DEF Tank Overfilled.
• Scenario #2 - Residual Ice in the DEF Tank or Covering the Level Sensor.
• Scenario #3 - DEF Crystallization Covering the Level Sensor.

Scenario #1... nope. was at 3/4 tank after filling.
Scenario #2 nope... was 39 degrees out, and had been all day before filling. Temp never dropped below freezing before driving, and was well above freezing during the drive.
Scenario #3: unlikely since the ECM reprogram solved the issue

Reading the TSB talks about a new sensor design in 2019+ and issues in cold weather, no problems found on the numerous failed sensors provided for failure analysis, tank filled too much, etc...

So... I feel the reprogram is a band aide to a problem caused by an inadequate designed sensor system.
It may not be common, but the colder weather here in upstate NY appears to play a part.

So I guess no more road trips after filling the DEF... or at least in the winter time.
The EPA requirement to effectively disable a vehicle due to a level sensor not reading correctly is ridiculous!

Anyone else experience this?
Any smart people with thoughts or experience on the matter?

Ping me if you have any suggestions not appropriate for a public forum.

 

[MikeXM]

My gauge has been indicating just below 1/4 full since early December (It ran correctly until the freezing temperatures). Back then I added 2.5G to see if it would move. It did not. Even if it was about 3/4 full. Oh well.

Then, yesterday, as for the first time it was above freezing temperature, I added another 2.5G. It almost took all of it, save for a few once. So, since it froze to 1/4, it still burned some DEF.
I hoped the warmer temperature and the new liquid would trigger it back to normal. But no. I have run about 30 minutes since. Still indicating a 1/4 full tank.

Doesn't really stress me out. When it get really warmer and if it still doesn't move, I'll have it checked.

 

[Brutal_HO]

Had the above warning come on yesterday while traveling for work. I was roughly 100 miles from home when this happened, so I turned around and immediately went home.
I had put 2.5 gallons of DEF in the tank the evening before, but noticed the gauge didn't reflect the addition. Was at 1/4 tank, so should've moved to 3/4.

Just finished up with the dealer who simply reprogrammed the ECM per a TSB (TSB number was not specified) referencing P203e code (reluctant level sensor).
The code makes sense, but the TSB leaves me perplexed.

I presume they are referencing TSB 18-034-21 which lists the following likely causes:
Scenario #1 - DEF Tank Overfilled.
• Scenario #2 - Residual Ice in the DEF Tank or Covering the Level Sensor.
• Scenario #3 - DEF Crystallization Covering the Level Sensor.

Scenario #1... nope. was at 3/4 tank after filling.
Scenario #2 nope... was 39 degrees out, and had been all day before filling. Temp never dropped below freezing before driving, and was well above freezing during the drive.
Scenario #3: unlikely since the ECM reprogram solved the issue

Reading the TSB talks about a new sensor design in 2019+ and issues in cold weather, no problems found on the numerous failed sensors provided for failure analysis, tank filled too much, etc...

So... I feel the reprogram is a band aide to a problem caused by an inadequate designed sensor system.
It may not be common, but the colder weather here in upstate NY appears to play a part.

So I guess no more road trips after filling the DEF... or at least in the winter time.
The EPA requirement to effectively disable a vehicle due to a level sensor not reading correctly is ridiculous!

Anyone else experience this?
Any smart people with thoughts or experience on the matter?

Ping me if you have any suggestions not appropriate for a public forum.

Fill the DEF and shut up peasant.

The only way to get rid of the DEF limp mode BS is an emissions intact tune that has the option to run without.

Get em while you can. Once the CP4 is gone...

 

[H3LZSN1P3R]

I just had this DEF was frozen so i thawed it then still never readjusted so i added more then it froze again then i thawed and drained the tank and put 2.5gal in still ran at low reading i then got the count down, went to dealer they did the same flash you referenced after a system check for the DEF proving nothing was wrong…. While i was there i was talking to the service advisor he mentioned there being 12 other trucks there this week similar issue but needing the crystalization cleaned off the pump or injector apparently what i did prevented them from having to take my tank out to clean it luckily…. I will be deleting the EGR and DEF after i get the CP3.3 swap

 

[Will_T]

The EPA requirement to effectively disable a vehicle due to a level sensor not reading correctly is ridiculous!

I have a big fear of this also and agree it is absurd. It should at least be 300 miles or something. There are many time I am out in the Nevada or Utah desert withour travel trailer and 100 miles or more from the nearest good sized town and even further from the nearest dealer. Going into limp mode out would be a disaster!

The only way to get rid of the DEF limp mode BS is an emissions intact tune that has the option to run without.

Get em while you can. Once the CP4 is gone...

I have seen this mentioned before but don't understand exactly what it refers to and all attempts to search for a thread on it here give me 0 results. Do you have a link to where I could read about what this is?

 

[sstoner911]

The only way to get rid of the DEF limp mode BS is an emissions intact tune that has the option to run without.

Emissions intact but no DEF....sounds like an oxymoron!

Or a trap hahaha

 

[H3LZSN1P3R]

Emissions intact but no DEF....sounds like an oxymoron!

Or a trap hahaha

No it still uses DEF just wont throw you in limp mode if there is an issue or if you run out of DEF you wont get derated

 

[CFE]

No it still uses DEF just wont throw you in limp mode if there is an issue or if you run out of DEF you wont get derated

That would be worth it - I'd be willing to outfit my rig w/ that tune in a heartbeat.

 

[MtnRider]

Emissions intact but no DEF....sounds like an oxymoron!

Or a trap hahaha

Emissions "intact" tuning leaves all the part there but disables the DEF/SCR (and EGR) so no DEF used, the DPF is still there and will regen as normal. Emission "compliant" tuning, everything still works as normal and uses DEF.

.

 

[sstoner911]

Emissions "intact" tuning leaves all the part there but disables the DEF/SCR (and EGR) so no DEF used, the DPF is still there and will regen as normal. Emission "compliant" tuning, everything still works as normal and uses DEF.

.

Ya I get it....my 2017 was a full delete....no EGR etc...

I tried searching bfor these tunes that are emissions complaint but I think Google has black listed a lot of these sites so hard get them in the search results much anymore. A few top distributers but nothing like in 2017!

May have to see what Duck Duck Go has.

 

[Brutal_HO]

Ya I get it....my 2017 was a full delete....no EGR etc...

I tried searching bfor these tunes that are emissions complaint but I think Google has black listed a lot of these sites so hard get them in the search results much anymore. A few top distributers but nothing like in 2017!

May have to see what Duck Duck Go has.

I don't think you're going to find any non-emissions complaint tunes on any us domains. They're all up nort der hey.

 

[H3LZSN1P3R]

I don't think you're going to find any non-emissions complaint tunes on any us domains. They're all up nort der hey.

Finally something in our favor!

 

[sstoner911]

That's one of the Issues that keeps me from tuning. Tech support I hear is a nightmare with some of these tuners.

 

[Will_T]

I just wish there was a way to simply eliminate limp mode. Or to reset it. Or to extend the mileage before it happens. I don't feel I need any more power or tuning on my truck. I also don't have a problem leaving all the emissions stuff intact. I just don't want to have to worry about limp mode if something like a DEF sensor goes out when I'm in the middle of the desert. It seems like the regulators that dictate things like this must all live in the crowded eastern part of the country. Some committee must have decided that a hundred miles or whatever is more than what is needed to get your truck to a dealer. But obviously it's not in a big portion of our country.

 

[H3LZSN1P3R]

I just wish there was a way to simply eliminate limp mode. Or to reset it. Or to extend the mileage before it happens. I don't feel I need any more power or tuning on my truck. I also don't have a problem leaving all the emissions stuff intact. I just don't want to have to worry about limp mode if something like a DEF sensor goes out when I'm in the middle of the desert. It seems like the regulators that dictate things like this must all live in the crowded eastern part of the country. Some committee must have decided that a hundred miles or whatever is more than what is needed to get your truck to a dealer. But obviously it's not in a big portion of our country.

Its also nice saving 50+$ a month not using DEF

 

[Will_T]

Its also nice saving 50+$ a month not using DEF

My point was just that for me, I'm willing to live with emissions the way it is. With my low miles, I probably only use five dollars a month in DEF. And if something breaks, I'm willing to get the dealer to fix it. I just don't want limp mode hanging over me every time I'm in the middle of nowhere.

 

[H3LZSN1P3R]

My point was just that for me, I'm willing to live with emissions the way it is. With my low miles, I probably only use five dollars a month in DEF. And if something breaks, I'm willing to get the dealer to fix it. I just don't want limp mode hanging over me every time I'm in the middle of nowhere.

I agree with that its down right dangerous i know my dealer is 25 mins away so if i had a de rate it would take me 3 hours to get there driving down a busy highway at 8km/h

 

[Will_T]

I agree with that its down right dangerous i know my dealer is 25 mins away so if i had a de rate it would take me 3 hours to get there driving down a busy highway at 8km/h

That is a good point. My concern is different but: Are there really some codes that put you in limp mode without any warning or leeway? I have not had it happen to me but from what I have deduced, a derate gives you a warning of so many miles before limp mode.

If a failed DEF sensor throws a code and forces me to go to a dealer to fix it, I am fine with that. I just don't want to be 200 miles out from anywhere, with no phone service and only have 100 miles before limp mode. And have that happen for a problem that does not make the truck undriveable, just "possibly" makes the exhaust temporarily a little dirtier.

Someone told me that if you have the ability to clear codes, you can clear a code like that and if it comes back, you have a new 100 miles at that point. I am not sure about the accuracy of that though. Like everything around this subject there seems to be wildly conflicting information. For example, some say you cannot clear codes without some sort of a bypass cable, even with a Banks iDash like I have. Others say you can do it with the iDash just fine and with no bypass and claim that they have done it themselves with no problem. Even Banks will tell you that you can do it. But some other very knowledgeable people say you can't.

 

[H3LZSN1P3R]

That is a good point. My concern is different but: Are there really some codes that put you in limp mode without any warning or leeway? I have not had it happen to me but from what I have deduced, a derate gives you a warning of so many miles before limp mode.

If a failed DEF sensor throws a code and forces me to go to a dealer to fix it, I am fine with that. I just don't want to be 200 miles out from anywhere, with no phone service and only have 100 miles before limp mode. And have that happen for a problem that does not make the truck undriveable, just "possibly" makes the exhaust temporarily a little dirtier.

Someone told me that if you have the ability to clear codes, you can clear a code like that and if it comes back, you have a new 100 miles at that point. I am not sure about the accuracy of that though. Like everything around this subject there seems to be wildly conflicting information. For example, some say you cannot clear codes without some sort of a bypass cable, even with a Banks iDash like I have. Others say you can do it with the iDash just fine and with no bypass and claim that they have done it themselves with no problem. Even Banks will tell you that you can do it. But some other very knowledgeable people say you can't.

I tried everything with my scanner that can do just about everything and it could not clear the code it could be a gateway issue but i am not sure

 

[Will_T]

I tried everything with my scanner that can do just about everything and it could not clear the code it could be a gateway issue but i am not sure

Well there you go. Perfect example. Some say you can, but your real-life experience is different. Maybe it depends on the code. I saw a thread a while ago that discussed what was needed to bypass the firewall/gateway. I may try to find that thread again and see about getting the cable, software, or whatever is needed so I have more options if the threat of limp mode does ever happen to me. If I can find the thread, I will come back and link it here for reference. As usual, it is very helpful to have this forum of users available so we are not on our own trying to figure out how to be best prepared.