My 2021 3.0 went into limp mode. The DEF tank is full. Hoping I can get it to the Stealership tomorrow morning. Anyone else have this issue?
Limp Mode
- Thread starter ms1095
- Start date
Teegunn
Well-known member
Yeah... I had it and was stranded out of state for a month because of it. Dealership had it for a month and could never get the "service emissions system" error to stay off, thus the truck was always in limp mode.
I traded that 2020 AT4 3.0 off for a 23 AT4X mostly because I could not be stuck out of state (working) any longer. It's an issue others have had, also.
Well after over 100 miles in limp mode it cleared itself as was pulling into the dealer today. What are the chances? They are still checking it out to see if there are any permanent codes stored. I really hope I don't have the issues that you went through. Sounds like a nightmare.
Teegunn
Well-known member
I hope it has cleared permanently for you. What was the error code/message that popped up on the dash? Mine was "service emissions system". Dealership replaced numerous (at least 6) sensors, some on the engine, some on the exhaust system, and none of it fixed it. It was like they were just guessing on what to try to do to fix it. I gave up and traded it off as I felt at that point it was going to be a problem consistently with that truck.
So far, so good with my 23 AT4X. 6.2 is thirsty, but with the difference between the price of diesel vs gas, it is a wash on the pocketbook. I just have way less range since both trucks have the measley 24 gallon tank. I figure I get about 5 MPG less on the 6.2 vs the 3.0, so about 125 miles less range on a full tank with the 6.2. The acceleration and power are clearly superior with the 6.2, but I rarely step into it. The 3.0 was torquey and quick, I had no complaints with the power with that engine.
Service DEF system and the check engine light. Threw 15 codes I was able to clear the CEL but the DEF light stayed on I was still getting code P2BAA Nox Exceedence - Low Reagent Consumption
Duramaximus
Well-known member
Yikes! Hope you get it figured out.
Teegunn
Well-known member
Yeah, I had the same code and the check engine light also. I could clear the code with my code reader, but that did nothing. The dealership would put in various sensors (the ones they could actually get - a lot of them were "out of stock", supply issues). I think the dealership was just clearing the codes after installing the sensors, but the "service emissions system" code would pop back up on my dash, and the check engine light also, a mile or so after leaving the dealership each time they tried a different fix.
I couldn't wait any longer to get it fixed, it literally stranded my for 4 weeks out of state (I had already been gone working for almost 4 weeks previous to this code and limp mode popping up), I could not wait any longer with no fix in sight. So I traded it off.
I know they must have "fixed it", as they sold that truck after I traded it off. I know this because my wife works in license and title in the county where I live in Montana, and she saw the title paperwork come in a few weeks ago from the dealership, so that means they sold it. I hope whoever bought it doesn't have continual issues with that truck. I know I had lost all confidence that these issues would be fixed. Felt like it would be a constant issue, basically making the truck unusable for me.
I hope your issue gets fixed for real, and it isn't an issue that keeps happening like it did on mine.
bobholthaus
Active member
Our 2024 diesel went into limp mode yesterday with 3500 miles on the odometer. Same “service emissions system” error as stated above. Thankfully we aren’t in Colorado (from St. Louis) like we are going to be next week. The dealer told my GF it has something to do with the DPF and it possibly being full. We will see what they find today. These diesels: I love them and hate them at the same time (I have ecodiesels in two Jeeps, and two duramax’s in a Yukon and the Sierra I’m talking about). We are a 4 diesel family.
JimP
Member
HAD A WEIRD ISSUe POP UP LAST WEEK. CEL COMES (I hate caps-lock) on and I start looking, tightening, etc. nothing. Make appointment with dealership - closest one was like four days out. On a hunch I filled the DEF tank and tightened the def cap and the light went out. Still out and no issues.
Oh...while crawling around under the truck I found the remnant of a bolt that sheered off hanging on a pice of equipment. It is color-coded blue marker on the end of the bolt so I kept it for the dealer when we get back to Texas. Hopefully nothing too important.
Oh...while crawling around under the truck I found the remnant of a bolt that sheered off hanging on a pice of equipment. It is color-coded blue marker on the end of the bolt so I kept it for the dealer when we get back to Texas. Hopefully nothing too important.
You need to re-state your love/hate relationship to something along the lines of...You love the diesels and hate epa/pollution control devices.
Is this an issue with the 1500 AT4 diesels only?
bobholthaus
Active member
Indeed I do. I love the torque and gas mileage... and wish I could go down the street for a delete...You need to re-state your love/hate relationship to something along the lines of...You love the diesels and hate epa/pollution control devices.
bobholthaus
Active member
I am not sure if the 6.2 goes into any kind of limp mode; I've never heard of a gas model in any brand go into limp mode. It's mainly due to the emmissions systems; when they get out of spec, the engine shuts off power to save itself, and to comply with the EPA (this is only a guess on this second part). I've experienced 3 of my 4 diesels in limp mode in the last 24 months; I'd love to know if this happens on gassers. But we modern day diesel guys are extremely aware of limp mode!
BTW, when it goes into limp mode, power is limited in RPM, so you can't accelerate and then you can't go above a certain speed. It's unnerving. If you're trailering on the highway and instantly you lose power and are limited to 40 mph (for instance), it scares the crap out of you. I was pulling a camper out of Denver into the foothills in bumper to bumper traffic doing 55 when it happened last year and I swear the guy behind me almost rear ended me and people were so pissed. But since I needed power to get up the incline, I was screwed and couldn't proceed. I pulled over, power cycled the ignition, and it reset (this was in my 2023 Wrangler Diesel - 2500 miles on it, almost brand new). It's not fun, and you'll know it the second it happens. It's like Uncle Sam's own governor gets slapped on your engine instantly!!
bobholthaus
Active member
Update: My GF talked to the dealer, so I never got the whole story, but here is the invoice from the dealership and what they said was the reason the truck went into limp mode; it appears from a quick Google search that the DPF went into some kind of failure mode and it shouldn't have, and this TSB fixed it (24-NA-094):
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