Bracket Talk
2015 Duramax 3500

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https://drr.infopop.cc/eve/forums/a/tpc/f/75460652/m/1867001307

February 02, 2026, 04:54 AM
Runner-up
2015 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
BTR69
Can'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.


William Kilduff
1970 Barracuda
1968 Camaro X2
1968 Caprice
1964 F100
February 02, 2026, 08:53 AM
B KING
quote:
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 Smile

https://www.amazon.com/dp/B0FL..._dt_b_fed_asin_title


1980 Camaro
Taking the Best Working Small Tire Shyt Box & making it Greater Than Before!
3100 lbs.
Pump Gas 436
February 02, 2026, 09:01 AM
CURTIS REED
Better 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. Didn't think of that Wouldn't have been too bad if he hadn't started it.