2017 Duramax Recommends Using Only GM DEF to Avoid Problems

jimstringer · August 11, 2017

I purchased a 2017 GMC 2500 HD Denali Duramax on May 21, 2017. I have driven it less than 8000 miles and have had it in the dealership 4 separate times because the check engine light came on.

They did “burn downs”, tightened a cold air pipe to the engine, and reprogramming the computer.

After driving more that 250 miles to and from the GM dealership and spending numerous days of my time dealing with this issue, I spoke with the dealership owner. He shared the following information:

After speaking with his GM regional representative, he was told that “GM programmed computers on 2017 GMC trucks equipped with the Duramax engine to detect any DEF that didn’t meet the exact same quality specifications as GM DEF”.

More plainly stated, GM is essentially forcing 2017 Duramax owners to buy GM DEF or there is a real chance the check engine light will come on and the vehicle could eventually go into shutdown mode.

This would clearly pose a problem for everyone that buys DEF from anyone other that GM. I have a motor coach that requires DEF. Farmers and other businesses that own 2017 Duramax equipped trucks, and have other vehicles requiring DEF would also be severely impacted. We buy and store DEF from third party sellers, because it is more convenient and much cheaper than buying DEF from GM.

NOTE: A service bulletin has just been released that requires owners to bring their vehicles in to have the computers reprogrammed. This is supposed to reduce the sensitivity related to DEF quality. I had this done to my truck and will do a follow-up post after I add NON GM DEF to my truck.

wade_660 · August 11, 2017

That pretty much mean that they don't know what's wrong with it or how to fix it. Therefore it must be your fault. As long as the def you're using is fresh, you're good

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diyer2 · August 11, 2017

I don't own a diesel but agree with wade evans ^^^^ and will ad

B.S.

jimstringer · August 11, 2017

Regarding the comment about using fresh DEF, I owned a 2014 Duramax and used DEF from AutoZone and SAMS, and had no problems with DEF quality. I used the same DEF I always used in the 2014 Duramax with no problems, but the same DEF causes the check engine light to come on in the 2017 Duramax. As much DEF as these companies sell, it is fresh.

The GM Service department says the computer is configured so that it only functions based on GM DEF quality standards. There are so many 2017 Duramax owners have experienced similar problems that it forced GM to issue a service bulletin on the problem. Maybe the fix recommended in the service bulletin will solve the problem.

Farmers and other businesses using a DEF by the barrel won't buy from GM because of the price differnece. GM needs to fix the problem.

Peterd · August 11, 2017

How wanted to use non GM DEF for the past four years. My 2015 at 98k went to the shop numerous times Finally corrected when the Cat, down pipe, injectors, etc. at the rate one one per week after checking the fuel and DEF was fixed. So I traded it in fear of having to repair it on my nickel next time.

Just traveled the country and bought DEF in Utah and Indiana, 21/2 gallons for $23 and change. Using approximately 1 1/4 gal. per thousand it would be nice to use other than GM DEF

GM should make all aware of the issues.

redwngr · August 11, 2017

From the 2017 Duramax supplemental owners manual:

"Locating Diesel Exhaust Fluid

DEF can be purchased at a Chevrolet or GMC dealer.

It can also be purchased at authorized vehicle and truck dealerships.

Additionally, some diesel truck fueling stations or retailers may have DEF for purchase.

For vehicles with an active OnStar® subscription, OnStar can help to locate a DEF retailer."

Seems like def from a truck stop or retailer is ok per the owners manual.

Edited August 11, 2017 by redwngr

COHauler · August 13, 2017

Right from the owners manual:

GM Diesel Exhaust Fluid or DEF that meets ISO 22241-1 or displays the API DEF certification mark.

Look at your diesel supplement manual.

I call bullshit. I keep all my receipts, so if GM ever tries this bull, they can choke on a bag of dicks.

Edited August 13, 2017 by COHauler

Doug Rosewood · August 13, 2017

I believe it's law that they cannot force you to use their parts/fluid..I forget the name of the act

Adamrg · August 13, 2017

]More plainly stated, GM is essentially forcing 2017 Duramax owners to buy GM DEF or there is a real chance the check engine light will come on and the vehicle could eventually go into shutdown mode.[/font][/size]

Not quite.

Right from the owners manual:

GM Diesel Exhaust Fluid or DEF that meets ISO 22241-1 or displays the API DEF certification mark.

As long as you have good quality def that meets this cert. you should be good, is what I got out of gm's response.

calgator73 · August 24, 2017

sounds like computer issue... hope it works out

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2017HD · August 25, 2017

Recently my DEF Low came on while towing - I added 5 gal of Blue DEF and have had no problems - 5gal for $28.00

Lions2018 · August 31, 2017

I've got 21,000 miles on mine and I've NEVER used GM DEF. I have always got it at the pump at Pilot, every time I have put it in. And I have never, ever seen the CEL, for anything on my truck.

5.375 Gallons @ 3,234 miles

5.980 Gallons @ 9,094 miles

5.317 Gallons @ 13,480 miles

5.417 Gallons @ 17,132 miles

jj46 · September 13, 2017

This is an ongoing problem that GM can't seem to figure out. There is a 19 page topic on one of the other forums. It has hit me as well. 300 miles and CEL, P20EE code. Some people have successfully lemon-lawed their trucks due to this, others have had many trips to the dealer having sensors replaced, DEF tank drained and flushed, injectors replaced, etc. only to eventually be told by GM corporate that "There is no fix at this time". The "contaminated DEF" was an initial guess but turned out to be false.

I'm very closely monitoring that other thread... a lot of nervous people who own trucks that this issue is affecting, on both 2017 and 2018 model years.

Edited September 13, 2017 by jj46

revrnd · September 19, 2017

I believe it's law that they cannot force you to use their parts/fluid..I forget the name of the act

https://en.wikipedia.org/wiki/Magnuson%E2%80%93Moss_Warranty_Act

I'm familiar w/ it because the snowmobile OEMs like to say you have to use their 2 stroke oil.

Reido113 · September 27, 2017

I recently took delivery of a 2017 GMC 2500HD Denali with the Duramax. As soon as I hit 300 miles, the CEL came on as well. Judging from the readings in this post, this might not be a fun ride... Fortunately I was just around the corner from the dealer and was able to drop it off immediately. The first tech plugged in a code reader. He didn't give me the code, but said that the sensors are showing as not reading. They admitted the truck into the service cue. I will provide updates on my experience.

jj46 - Can you please hint a tad more as to where that other post that you at referencing is located? Sounds like I'd better get more educated on this.

p.s. I have not even driven enough to add fuel, nor any other fluids such as DEF, to my vehicle.

p.s.s. jj46 I believe that I found the lengthy post that you were referring to. Since I am not sure if it is kosher to redirect on this forum, I will refrain from linking.

Edited September 27, 2017 by Reido113