Is the DEF Limp Mode Threat a Myth? Why am I still able to drive normal? RAM 2500 DEF issues 

Thanks @Dan Willey, that would definitely be safer to not force someone into limp mode mid drive. Had I know that I would have done the same thing and just kept driving home the night it began having issues and not slept in a parking lot overnight waiting for a dealership to open to reset me 😂 live and learn. Also, in this video, I did turn it off and back on maybe 30 seconds or so after I hit zero (since I was in the dealer parking lot) and I still didn’t go into limp mode, but, it was right away, so maybe I’d have needed to wait for a few minutes before turning it back on again 🤷‍♂️. Thanks for the comment!

The truck will hit zero and keep going until you try to refuel or extensive idle or turn off truck. So if you get this message and are on road fill up truck before you hit zero miles and you will be able to keep going to get home.

Mine didn’t drop luckily, if anything they improved slightly, but I’ve heard a lot of guys had it drop.

@Thierry Charbonneau thank you for those tips. I’ll figure out how to do that for next time 🙏

I disconnected the battery - after about 30 minutes I attached it again. The codes were still there, but, NOW I COULD CLEAR THEM. Before, I tried to clear them - but - could not. Disconnecting the batteries let me do that, but, after connecting the battery again.

Heck yeah that’s for that tip. I’ll keep that in my memory bank for a future solution when that happens 🙏

Not true, didnt work on 5500 cummins

No it doesn't

@@user-ph3dg5zo1n i got the same message, come to find out wires of the def pump got cut. Idk. Connected with new wires and fixed the issue

Here's what I did, and it worked. First time - Portola, CA - i have a 2016 2500. We turned it off and reset the codes. The reducdent fluid code came up in several places. That worked. A year later - Drove up to Portola again. This time, resetting the codes did not work. We did it several times. Did not work. Then I disconnected the batteries (BOTH) for about 2 hours while we cooked dinner and ate. Reconnected the batteries and took it to my friend at Sierra Garage. He reset the codes for me. And it worked. Now - I've driven it up to S. Lake Tahoe. DANG. I have to do it again. So now. Since my friends garage is about 150 miles away. I will go buy an OBD reader and reset it myself. As a side note. I'm driving the truck up from sea level, Sonoma County, California. First time - my DEF gauge was 1/2. Second time it was 3/4 and this time - it's FULL. Did not get the CHECK ENGINE light on the first time or this time .. only on the 2nd time when I had to disconnect the batteries.

@Rob Casebolt ok, so I may have turned it off and back on too quick. Dang, sounds like you weren’t so lucky though. Hopefully your drive to the dealer wasn’t too long 😬

It’s had its issues but overall it’s a good truck.

Yes, the tank is full. It was threatening limp mode because the DEF system isn’t working and needed to be serviced, not because DEF was low. A few videos before I go over when it broke and made my truck wig out for 45 minutes before it would finally start and let me drive a bit.

@aaron green well it’s nice that you could delete those and even though it kinda knows it, it doesn’t go limp. Probably LH the only co sequence other than the light is improved fuel economy and a longer lifespan 😂

@Gavin Walker thank you for the response, and that's no lie about the mpg increase, it raised around 4 n a half miles, nothing out of this world but for me, I'm happy with it. Thanks again brotha

@aaron green of course brotha! And dude, that’s like a 30% increase, that’s huge! For me that would save me like $150 a month in fuel cost. I’ll have to look into how to get that done in Utah, and how to jump through the emissions hoops. Is it better to wait until my warranty is up you think? I imagine pulling it out early may cause problems?

Yeah, I was being modest ahaha I'm extremely happy on the increase. You should definitely definitely wait at least until you get close to the end of the latter part of your warranty or the end because to my understanding-(I'm newish to the deletes/tuner/programming, and diesel life)-you void the warranty on anything to do with what you've deleted, and if taken to the dealership I've read that by law they are required to flash your trucks computer. (making sorta what happened to mine with the message appear but worse apparently) and like California I'm not even allowed to drive there are several downsides but also several ups. That huge increase in gas mileage, the exhaust system theoretically is gone so regens or dpf problems that cost $3k-7k to clean is no worries, also I'm telling you that the moment I started the truck and tested it I could not believe the difference in performance/sound/power/ it swear it was night and day difference almost felt like it was a different truck I was shocked could not believe the difference and was stunned to find out alot more about that so-called emissions system uselessness reading forums and such, but that all being said make [SURE] to research before and if you do this. For me, 100% worth it I'd 100% do it again the improvements to the truck are too great to not.(I read somewhere also some dealerships will work with you mb I forgot to mention this) sorry for the long response lol

@aaron green I appreciate the long response, seriously. It was thoughtful and informative, I hope everyone reads it! I’ll definitely look into it towards the latter part of my warranty 👊

@Longsnowsm Hahaha that’s exactly what it’s like 😂

@DrinkingNDriving correct, it didn’t go into limp mode. I did learn that it won’t go into limp mode during the drive when it hits zero. Makes sense because that could be very dangerous if someone is on the freeway and their speed drops to 5mph. I did turn it off for a second in the video, and someone else said it’ll have to be off for several minutes to then go into limp mode and I simply cycled on and off too fast. So, who knows. 🤷‍♂️

Utah, American fork area

@David Cochran it was still broken then, but I found out it’ll never drop down your speed during that drive, which makes sense safety wise. And when I cycled the engine it was too quick, it has to be off for several minutes at least. But the problem ended up being in the PCM not the DEF system, so maybe that played a factory 🤷‍♂️ who knows, this programming is all zeros and ones and is way beyond me brain capacity haha

😂 hahaha @S Tex not suspicious at all 🤔

@@gavinwalker5686 well at 67500 or so miles your truck and dealer knows it time to spend some money, doesn’t matter if it needs it or not. Yes very suspicious!

Will do! I have a partial update video I’m posting soon, but no idea on what cost would be yet (it’ll all be covered under manufacturer warranty) but when I had the codes cleared on my last video during the trip home, there was no cost.

That makes sense how they wouldn’t just suddenly drop your speed down. I wasn’t sure though 🤷‍♂️ so camped it! Next time I’ll just keep it on and get home. I typically don’t shut it off the refuel anyways.

Dude! That’s a great little fix hack!

@@gavinwalker5686 Too bad he has posted it here in various replies, over and over and over...

Where is that sensor, what’s it called?

@Michael Cox I kinda wondered, because it didn’t activate even after I turned off and back on again. So that’s just to get you in, and only if you’re actually out of DEF would limp mode get activated?

@Al Ninahuanca good to know there is a little grace period until it actually kicks you down.

Utah, northern Utah county.

Yep. Bad pcm turns out. There’s more videos on that.

But the fix was solid. No problems related to it since.

Don't forget to clean your EGR defuse tube as a regular your engine will catch fire

@trevorashton4598 thank you, I wasn’t even aware that was a thing.

If only other things still worked that good in limp mode 😂😂

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