2017 Duramax Recommends Using Only GM DEF to Avoid Problems

[jimstringer]

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.

[Heavy 5.7]

I think your frustration should be directed towards the EPA not GM.

[newdude]

We've had issues on 2011-2016 trucks with GM DEF, so I wouldn't say that aftermarket DEF fluid is a direct cause. As long as its fresh DEF, no more than 6 months old shelf life, you should be fine. I would be examining your source of DEF and see the freshness of it.

 

There are no documents that I can find that say GM mandates the use of ACDelco DEF. I see no bulletins, PIs, or any other documents for reprogramming for this either. There is one for NoX codes and a wiring corrosion concern, and there is a bulletin for an abnormality in the ECM and TCM program that leads to drivability concerns but that's all I see.

 

The owners manuals state:

 

Diesel Exhaust Fluid (GM Part No. 19286291, in Canada 88862660) or diesel exhaust fluid that meets ISO 22241-1 or displays the API Diesel Exhaust Fluid Certification Mark.

 

Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)

 

A supply of clean, fresh Diesel Exhaust Fluid (DEF) is critical for optimum Selective Catalyst Reduction (SCR) efficiency. SCR efficiency is determined by monitoring the Nitrogen Oxide (NOx) sensors located upstream and downstream of the SCR. This vehicle provides the driver with an elaborate series of prompts and warnings that are initiated when the Engine Control Module (ECM) detects a drop in the SCR NOx reduction efficiency suggesting a diluted or contaminated DEF supply.

 

When contaminated or diluted DEF is suspected, the ECM initiates the DEF Quality warning process. Once initiated, DEF quality warnings grow increasingly more serious as the vehicle continues to be driven. The vehicle’s current DEF quality warning status is displayed on the scan tool. When a drop in SCR efficiency is detected, the normally Off Reductant Field Quality Warning Indicator Command will display Warning Level 1 through Warning Level 11 depending on the number of miles driven. The series of DEF Quality Warnings alert the driver that DEF system service is urgently needed.

Warning Level 1

Warning Level 1 is triggered when the ECM first detects the SCR efficiency is below a calibrated value. The Driver Information Center (DIC) displays the following messages:

For Non-Emergency vehicles and Emergency vehicles MY 2013 and older:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• 160 km (99 miles) until 105 km/h (65 mph) Max Speed

For Emergency vehicles MY 2014 and newer:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• 999 km (620 miles) until 105 km/h (65 mph) Max Speed

The messages alternate every 5 seconds until acknowledged by the driver; however, the mileage countdown remains displayed in the DIC. The DEF Indicator in the instrument panel is illuminated.

Warning Level 2

Warning Level 2 is triggered after the first mileage countdown expires without a DEF fluid service. The driver will hear 4 chimes on entering Warning Level 2. The DIC displays the following messages:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• Transitioning to 105 km/h (65 mph) Max Speed

The messages alternate every 5 seconds until acknowledged by the driver; however, the Transitioning to 105 km/h (65 mph) Max Speed remains displayed in the DIC. The DEF Indicator in the instrument panel is illuminated. Vehicle speed limit is ramping down from max speed limit to the limit of 105 km/h (65 mph).

Warning Level 3

Warning Level 2 automatically advances to Warning Level 3 after speed limit ramp down is complete or a key cycle. The driver will hear 4 chimes on entering Warning Level 3. The DIC displays the following messages:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• Speed Limited to 105 km/h (65 mph)
• 120 km (75 miles) Until 89 km/h (55 mph) Max Speed

The messages alternate every 5 seconds until acknowledged by the driver; however, the speed limitation and mileage countdown remains displayed on the DIC. The DEF Indicator in the instrument panel is illuminated.

Vehicle speed is limited to 105 km/h (65 mph).

Warning Level 4

Warning Level 4 is triggered after the second mileage countdown expires without a DEF fluid service. The driver will hear 4 chimes on entering Warning Level 4. The DIC displays the following messages:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• Transitioning to 89 km/h (55 mph)

The messages alternate every 5 seconds until acknowledged by the driver; however, the Transitioning to 89 km/h (55 mph) remains displayed in the DIC. The DEF Indicator in the instrument panel flashes continuously. Vehicle speed limit is ramping down from 105 km/h (65 mph) max speed limit to 89 km/h (55 mph).

Warning Level 5

Warning Level 5 is triggered after the speed limit ramp down is complete or a key cycle. The driver will hear 4 chimes on entering Warning Level 5. The series of 4 chimes will repeat 3 additional times every 3 minutes . The DIC displays the following messages:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• Speed Limited to 89 km/h (55 mph)
• 120 km (75 miles) Until 7 km/h (4 mph) Max Speed

The messages alternate every 5 seconds until acknowledged by the driver; however, the speed limitation and mileage countdown remains displayed in the DIC. The DEF Indicator in the instrument panel flashes continuously.

Vehicle speed is limited to 89 km/h (55 mph).

Warning Level 6

Warning Level 6 is not used.

Warning Level 7

Warning Level 7 is not used.

Warning Level 8

Warning Level 8 is not used.

Warning Level 9

Warning Level 9 is not used.

Warning Level 10

Warning Level 10 is triggered after the third mileage counter expires without a DEF fluid service. The driver will hear 4 chimes on entering Warning Level 10. The DIC displays the following messages:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• Transitioning to 7 km (4 mph) Max Speed

The messages alternate every 5 seconds until acknowledged by the driver; however, the Transitioning to 6 km/h (4 mph) Max Speed remains displayed in the DIC. The DEF Indicator in the instrument panel flashes continuously. Vehicle speed limit is ramping down from 89 km/h (55 mph) max speed limit to 7 km/h (4 mph).

Warning Level 11

Warning Level 11 is triggered after the speed limit ramp down is complete or a key cycle. The driver will hear 4 chimes every 3 minutes on entering Warning Level 11. The series of 4 chimes will repeat every 3 minutes. The DIC displays the following messages:

• Exhaust Fluid Quality Poor
• See Owner’s Manual Now
• Speed Limited to 7 km (4 mph) Max Speed

The messages alternate every 5 seconds until acknowledged by the driver; however, the Speed Limited to 7 km (4 mph) Max Speed remains displayed in the DIC. The DEF Indicator in the instrument panel flashes continuously.

Vehicle speed is limited to 7 km/h (4 mph).

 

[Cowpie]

That is the key... the shelf life or how "fresh" the DEF is.  Best place to get DEF tank filled on a pickup is at a commercial truck area.  High volume commercial truck fueling sites, commercial truck service shops, dealerships, etc.   And it is usually far cheaper than at the pump and definitely cheaper than any off the shelf stuff.  All of the commercial service areas in my area will allow anyone, even someone with a diesel car, to come in and they will top off their DEF tank.  Current price about $1.79 a gallon.    One has a HD engine.  Stop acting like the average car owner and go where the HD stuff is.  The Mack truck dealership near me will fill the DEF tank on anything that is brought in, from a diesel Cruz on up thru heavy commercial trucks.  And they go thru the DEF... like a couple of 275 gallon totes of the stuff per day.  Their stuff is about as fresh as it gets.

 

The DEF a GM dealership has is made by the same folks that make all the other DEF on the market.  GM does no in house quality testing and other stuff.  It is packaged by the same folks that do all the other DEF and got the contract.  EPA regulations regarding DEF are pretty tight.  Not like someone is mixing the stuff up in their garage and selling it.  But the industry standard is to not use any DEF that has sit more than 6 months since it was made.  Shelf life is critical with DEF.