DPF Values from Engine Control Unit

Good day.
I'm new here. I recently purchased the VCDS set from Dieselschrauber.

I have a T5 (BRS) with a DPF. The vehicle now has 250,000 km on the odometer, and it smells strongly of exhaust fumes. It's possible that parts of the monolith have become detached. The check light is not on, and the engine is running well. It might be pulling a little sluggishly, but I can't really compare it to how it used to be.

I want to test a DPF that belongs to a friend. It's not an original part. After experiencing problems with aftermarket filters, I want to read and save the relevant values of the old filter (e.g., ash content) before discarding it.

If the aftermarket filter continues to cause problems, the old DPF would have to be reinstalled until October for financial reasons.

My question is: Which data from the MSG do I need to read and store?

Could the "create memory image" function potentially help with that?


Thank you very much.

bonobo

Hi,

Please review the following topic:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Hello.
And be aware that many T5s suffer from exhaust leaks due to damaged exhaust manifolds, which can cause an exhaust smell inside the vehicle! You can easily find out if your engine is affected by searching online.
haithamina

OK - thanks for the information so far.

The engine seems to be leaking near the exhaust manifold. It's the smaller 1.9-liter engine, and from what I've read, the exhaust manifold issue mainly affects the larger 2.5-liter 5-cylinder engines. I've already examined the engine block closely using an endoscope/video camera.

What I definitely found online is that the DPFs can fail. The cubes inside can break out. And the smell of this T5 is almost unbearable. It can give you a headache. A friend of mine has a Golf Plus TDI - without a DPF, with Euro 4 emissions. It doesn't smell as bad as the van.
After 250,000 kilometers, the filter is also very likely to be full of ash.
But, as mentioned before, there's no warning light... everything is fine (for the electronics).
The DPF in question is likely a coated DPF, which thus functions as an oxidation catalyst (OXI-CAT) at the same time. (The G Plus only has one OXI-CAT). Due to the missing internal structures within the DPF, the filter lacks any blockages and is completely open. Furthermore, the remaining channels cannot be used due to the high ash content. Therefore, my assumption is that the exhaust gases are simply forced out through the center.


I was already familiar with the thread about the DPF logs. Basically, I bought VCDS to log and analyze the data.

I'm trying to figure out the learning values for the MSG (Message Security Gateway) function "Preserve," so that I might be able to reuse the old filter.

If there's a smell of exhaust fumes in the car, it's likely due to leaks in the exhaust system, but probably not caused by internal defects in the DPF (Diesel Particulate Filter) or the catalytic converter. With older diesel engines, you wouldn't normally smell anything inside the cabin.
If the exhaust fumes smell strongly and acridly (which you can tell when you're standing next to the vehicle), then it indicates a combustion problem.
You can only smell diesel exhaust fumes from a warm, functioning engine outdoors, even without a DPF (Diesel Particulate Filter) and/or catalytic converter, if you put your nose directly into the exhaust pipe.
hg
Herbert.

My understanding has been that a faulty DPF with higher back pressure can also lead to leaks; in any case, I have read this in several forums.
For some people, the odors in the car disappeared after the DPF was replaced.

Comparing the (smell) of a direct injection PD or CR engine to an older pre-chamber diesel (if that's what you meant) is, in my opinion, explainable. The higher pressures result in significantly more nitrogen oxide (due to a higher combustion temperature, also due to better combustion). That's why we have exhaust gas recirculation (EGR) technology. Mixing exhaust gases lowers the combustion temperature. Nowadays, we have exhaust coolers, intercoolers, etc. Older PD TDIs almost always have an oxidation catalyst (OXI-Kat).

But maybe you're right, and my car isn't broken .

Do you just have the exhaust smell, or are you also experiencing performance issues?
I initially had a T5 BRS with exhaust fumes and reduced power, and the EGR valve was the cause.
You can see the DPF values starting from byte address 67.

Before I delve into speculations about the origin of the smell, I would start by checking the exhaust system for leaks. Whether or not the EGR valve is defective (if it were defective and open, a fault code should appear quickly, and the nitrogenous gases that the person claims to smell might not be produced due to the lack of combustion chamber temperature).

The test definitely takes much less time than any writing. No one can rule out the possibility of a faulty catalytic converter or DPF. However, this often leads to high back pressure in the exhaust system, which becomes noticeable while driving. Without any leaks, the smell can only originate from the intentionally open end of the exhaust system.

...so, I think I'll start at the beginning, because it's not really that complicated.