February 02, 2026, 04:54 AM
Runner-up2015 Duramax 3500
Have had the warning light coming on for some time about the DEF system. Just turned it off for the last @25,000 miles. Since it's gotten very cold, seems to be coming on more. Due to age and miles of 125,000 I don't want to spend the busks on a new DEF tank. Anyone got any suggestions. Considering just bypassing the whole system. Suggestions. By the way, it's still been using DEF fluid.
February 02, 2026, 08:06 AM
BTR69Can't speak for Duramax, but my 2018 Ram 2500 gave me a DEF warning a while back. It was still working, but apparently not properly. Turned out to be a failing DEF injector. Easy fix, about 15 minutes, but expensive part that is dealer only for mine. Good luck.
February 02, 2026, 08:53 AM
B KINGquote:
Originally posted by Runner-up:
Have had the warning light coming on for some time about the DEF system. Just turned it off for the last @25,000 miles. Since it's gotten very cold, seems to be coming on more. Due to age and miles of 125,000 I don't want to spend the busks on a new DEF tank. Anyone got any suggestions. Considering just bypassing the whole system. Suggestions. By the way, it's still been using DEF fluid.
Try this, it might be too late, but you never know. Read the description it talks about the code. I use it with the cheaper DEF but not with the premium DEF.
2BKING
https://www.amazon.com/dp/B0FL..._dt_b_fed_asin_titleFebruary 02, 2026, 09:01 AM
CURTIS REEDBetter just a failed part. One of my guys in my shop recently bought a 1/2 ton Chevrolet with the small diesel in it. He has never owned a diesel before and last week it happened. He put DEF in his fuel tank. $6,000-$8,000 oopsy.
The worst part though is he realized what he had done and started it to see how bad it would run.
Wouldn't have been too bad if he hadn't started it.
February 13, 2026, 07:40 PM
rustysadly there is a recall on that model up to 100000 miles
February 13, 2026, 10:22 PM
BP7582015 has def heater issues and also melted connections.
February 14, 2026, 06:35 AM
Curly1Do not quote me on this but I believe Trump passed something that allows you to eliminate the DEF system on Diesels as of Jan 1, 2026?
https://postimg.cc/gallery/np3zpruo/"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.
Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.
4X NE2 CHAMPION. 2020 TDRA NE2 Champion
February 14, 2026, 07:48 AM
Larry WoodfinBruce, I also heard that about emissions system rules being relaxed, but like you, I need to learn more. If it is true, it could greatly reduce the cost of new cars.