- 8,455
- 2,551
- 113
- Location
- Monrovia, Ca.
DEF is part water and part something else, don't remember, it has been a few years since I left the workforce, used to know, but now kinda don't care. It is made to defrost at the same rate as the water it is mixed with, hence the heating system in the DEF fluid side. In the aftertreatment system, there are O2 sensors, usually at the exit of the turbo, entrance to the aftertreatment system, don't matter if it is a single or dual type, and at the exit of the system. The OBC, ECM, whatever you want to call it, will KNOW what the system is doing by the O2 readings and dose as needed. IF the guy has done nothing to the programming of the ECM, it will log a fault, derate and eventually shut the engine off due to inefficiency at the NoX reduction part of the aftertreatment.Just a little off topic but theres a guy on you tube bought a new truck diesel and hes been documenting this from the first day till today for the last 130,000 miles hes been putting garden hose water in his def tank and has not had one problem /code . That just makes me smile at all the money people have spent buying def all these years
VW did some programming tricks that defeated aftertreatment operation, engineers at ARB were positive that there was a programming issue on the manufacturing end when they tested the vehicles, they were fine on emissions when stationary, but under load, they were way off. After years of questions, VW admitted to the programming issue, hence the VW buy back a few years ago.
After the VW fiasco, ARB went out and bought used diesel powered vehicles and hooked up a shiat ton of test equipment to see what the engines with miles/hours were doing. I was involved in the Cummins testing. The C powered things did fine, did just as the factory intended.....Cummins had DEF equipped engines in Europe 5 to 7 years prior to the intro here in the US, and they were working as expected. I talked with the ARB guys that brought the vehicles into the place I worked, and they said all were doing what the mfgrs stated they would/should do. Their job was to try and defeat the systems, including just water in the DEF system, unplugging, jumper plugs, and, yes, pee. All the engines tested, Cummins, Volvo, Mack, Isuzu, MB, Iveco, etc passed.
I find it EXTREMELY hard to believe that the guy on YouTube defeated the system with just water and no programming tricks.
Just my
![2 Cents 2cents 2cents](https://www.steelsoldiers.com/images/smilies/icon_smile_2cents.gif)
Edit, I forgot, there is also a DEF concentration sensor in the tank......