Error 0575: Rule Difference - Troubleshooting Guide

Hello everyone,

First of all, I want to express my greatest respect to everyone in this forum. The amount of knowledge available here is truly amazing.
However, I'm still stuck and can't progress any further just by reading. The story is as follows:

Approximately 4 weeks ago, my turbocharger failed on the highway. It suffered a bearing failure, triggered a limp mode, and all the engine oil was sucked through the intake manifold, burned inside the engine, and expelled as a thick cloud of smoke from the exhaust. Since I was far from home, I drove another 100 km back home. The oil level was sufficient for that distance. Then, I took it to the workshop. They replaced the turbocharger, cleaned the intake manifold of oil residue, cleaned the EGR valve, and cleaned the intercooler. They also replaced the catalytic converter (including what I believe is called the downpipe). I saw the old turbocharger, and it was completely coated (about 1.5 cm thick) with a layer of oily sludge. The pipe leading to the catalytic converter would have looked the same, which is why it was also replaced.

So far so good. After the repair, I'm still experiencing the problem with the error mentioned above. Leaks can be ruled out because there is absolutely no soot visible. I then purchased a diagnostic adapter and VAG Com and performed several test drives, recording the data graphically. What's noticeable is that the boost pressure only increases in conjunction with the engine speed. The control unit isn't sending any requests to the turbocharger pressure control valve for more pressure.

The right-hand side of the graph should always be considered.



You can clearly see from the bright line that the duty cycle actually increases slightly to reduce the pressure. I then repeated the same test in the fourth gear. In that case, it didn't reach the emergency mode, but even there, the control signal for the regulating valve shows very little activity. Here is a picture of the recording.



Right now, I'm just at a loss and don't know what to do next. The only thing that comes to mind is that about 5 years ago, a similar phenomenon occurred with the old loader (emergency mode on hot days under heavy load). After that, I took it to the VW workshop, and they mentioned something about excessive boost pressure. After the "repair," the car had less power, and fuel consumption also decreased by about 0.5 liters. However, the problem was gone. No parts were replaced. Could it be possible to program the boost pressure, or certain parameters that influence it, in the engine control unit?

My thinking is that the old loader had some kind of problem. That's why the pressure regulation in the control unit was adjusted. Now we have a new loader, and the old pressure regulation doesn't work anymore. Could this be the reason?

I would appreciate it if some more experts could look into my problem. I really want to be able to overtake trucks again without feeling anxious.

Thank you very much in advance.

Holger.

drewsho wrote:

Is it possible to program the turbocharger boost pressure, or certain parameters that influence it, into the engine control unit (ECU)? My thinking is that the old loader had some kind of problem. That's why the pressure regulation in the control unit was adjusted. Now there's a new loader, and the old pressure regulation doesn't work anymore. Could this be the reason?

Hi Holger,

Yes, it is possible to program certain parameters in the engine control unit, but that would be considered chip tuning and was certainly not performed by Volkswagen.

Unfortunately, I'm having a problem with your images because I don't understand the offset of the curves and the absolute values associated with them. Please read the technical article on how to adjust logs. To do this, go to the upload section and read the article by Rainer titled "Here's how it's done." It contains a relevant link.

Please upload the Excel sheet to the designated area and post a link here, and we will certainly be able to help you quickly.

Best regards,
Hendrik.

Hello Hendrik,

Which Measurement Work Breakdown Structures (MWBS) do you think are relevant and should be logged? Definitely block 11. What other information is needed?

Regards,

Holger.

drewsho wrote:

The right area of the graph should always be considered.

Hi,

In the lower image, I notice that the yellow curve drops sharply and then rises slightly again, even though the RPM is decreasing. This is typical of collapsing intake hoses or other blockages that only occur at high airflow rates, which naturally require the turbocharger to work extremely hard and achieve very high speeds.

Please check all air passages leading to the compressor inlet for leaves, forgotten rags, soft hoses, and any signs of delamination on their inner surfaces.

Hello Ulf,

"I'll do that as soon as I get home and the engine has cooled down somewhat. The area there isn't particularly long and consists of a rigid plastic pipe or a flexible plastic pipe. Before that, you only have the mass airflow sensor (MAF) and the air filter, which is also new. But who knows, maybe there's actually a piece of cloth stuck in the intake manifold. At first, I briefly ran the engine without the MAF and air filter by disconnecting the intake hose after the MAF. Then I held the hose with my hand to see if the engine would stall. However, only the rubber connectors after the turbo were sucked in, so I quickly let go again."

Regards,

Holger.

Shouldn't the MSG (wastegate) reduce the duty cycle to encourage the turbocharger to build more boost? Instead, the duty cycle is slightly increased. See image 1, where it says "almost no regulation of the boost control." In the second image, there is also no change in the duty cycle visible. The pressure increases solely due to the increase in engine speed. Now, let's take the same picture from the same distance again, but this time in 3rd gear.

drewsho wrote:

Shouldn't the MSG decrease the duty cycle to make the charger build up more pressure?

Theoretically, yes.
However, within the software, there's a designated area from which the TV signal cannot escape.
If your TV quickly starts accelerating towards the top of its range when you increase the input signal, because there's no luminance difference (LD) being received, it will get stuck there, even if the error between the desired and actual values continues to increase.

If the TV signal values were clearly visible, one could check whether the corridor explanation is correct.

Okay.

Okay, I'm now going to try logging the measurements as an Excel table and posting it here. I've already checked the intake manifold, and it's clean. Are there any standard values for a properly functioning AFN engine that I can use as a reference point to identify which value is out of range?

So, habe nun zwei Log-Fahrten gemacht. Selbe Strecke wie immer. Leicht ansteigend, ab Ortsausgang Vollgas. Jeweils im 3. und im 5. Okay.
Perhaps someone could take a look at this sometime.

/viewtopic.php?p=114171#114171

Thank you in advance.

Holger.

Quote:

Müsste das MSG das Tastverhältnis nicht verringern um den Lader dazu zu bewegen mehr Druck aufzubauen? Statt dessen wird das Tastverhältnis noch leicht erhöht. Siehe Bild 1 wo "kaum Regelverhalten der Ladedrucksteuerung" steht. Im 2. Bild ist ebenfalls keine Regung im Tastverhältnis zu erkennen. Der Druck steigt alleine durch die Erhöhung der Drehzahl an. Mache jetzt das gleiche Bild von der gleichen Strecke nochmal im 3. Gang.

You could try buying a new engine control unit (ECU) as a test; perhaps the old one has "forgotten" how to control the turbocharger due to age and wear.

Okay, just kidding... what your MSG (Motor Steuergerät - Engine Control Unit) is doing actually makes sense. The reason the turbocharger isn't hitting its maximum pressure limit despite the difference in regulation is due to the pre-injection map. However, it's achieving the maximum possible boost level within each operating point.

Quote:

So that at least we have some indication of which value is going out of control?

Your turbocharger isn't producing any boost pressure, even though it should be, which is why it also goes into limp mode after a while.

I would start by familiarizing myself with the hardware used to control the VTG (Variable Turbine Geometry). First, I would perform a basic configuration in module 11 and observe how the VTG moves.

If that's the case, then intake and exhaust blockages, or the turbocharger itself, are still potential causes.

Is this a "refurbished" replacement charger? We've had issues with those before.

Hi,

I agree with Malte. The control is permanently set to maximum pressure, so that's okay. However, the charger isn't responding adequately.

Regarding the battery replacement: You mention that a workshop did the work. Shouldn't you have a warranty on their workmanship? Why are you dealing with it yourself, then? But I'm just curious.

I agree with Malte's approach. Use the actuator test to see if the VTG is working (or check during startup, if you don't have a full version of VAG-COM). I suspect the VTG probably won't move at all. Then, check the vacuum hoses and manually test the VTG for movement.

If the VTG (variable turbine geometry) is moving, then there might be restrictions or blockages on the intake or exhaust side, or a faulty turbocharger. Since you mentioned replacing the catalytic converter due to heavy deposits, I'm surprised that the rest of the exhaust system is supposedly clear. It might be worth testing by letting the exhaust out after the catalytic converter and taking it for a test drive (be careful, as this would likely be very loud and not approved according to road traffic regulations). If the old turbocharger has shed pieces into the intercooler, then the intercooler should also be thoroughly cleaned or replaced.

Regards,
Hendrik.

Hello Hendrik, Hello Malte,

Thank you very much for the effort you have put in so far. )))

So, if the control system seems to be working correctly, then I suspect the problem might be on the exhaust side. The turbocharger itself is already producing the desired pressure of approximately 1 bar at high engine speeds. However, this only happens at engine speeds above 4000 RPM. I've visually inspected the VTG (Variable Turbine Geometry) rod and it seems to be moving freely. After starting the engine, the rod is positioned about 1 cm higher. At the moment, the possibility of a blocked exhaust system seems most likely to me. I need to find a way to check this. Is there a way to measure this without disconnecting the exhaust pipe after the catalytic converter? It's probably going to be very loud.

Regards,

Holger.

drewsho wrote:

So, if the control is okay, then I think it might be related to the exhaust side. The turbocharger itself already provides the desired pressure of about 1 bar at high engine speeds. But only at speeds above 4000 RPM. I have at least visually checked the adjustment of the VTG rod. It moves. So, after starting the engine, the rod is approximately 1 cm higher. At the moment, the possibility of a blocked exhaust seems to me the most realistic option. I will try to check that somehow. Is there a way to measure this without disconnecting the exhaust pipe behind the catalytic converter?

One could try to get an indication of the relationship between air mass and boost pressure. The MWB 10 is best suited for this purpose because both values are output "at the same time."
Okay, so drive it again for two more logs as before (in 3rd and 5th gear) with maximum torque at 8 and 10.
You can omit "MWB 3" here - instead, it would be great if you could format the data directly as numbers in the log .

Have you ever tried checking if the charging pump shaft still rotates freely with just two fingers (after removing the intake manifold)? A difficult-to-turn pump could potentially cause similar problems.

Okay, I can do that tonight. I definitely will. I'll post the logs afterwards.

Thank you for the tips.

Holger.

Writing on a forum is one thing, but working on your car during work hours is quite another.

Okay everyone,

I removed the exhaust pipe after the catalytic converter and drove my car on my usual route. Unfortunately, there was no improvement in performance. The boost build-up is still too sluggish. I logged two drives, in 3rd and 5th gear. This time, I recorded data from blocks 8, 10, and 11. I'll post them after I've cleaned them up a bit.
I also disassembled the intake manifold to see if the turbocharger was running smoothly. While it could be turned easily with my finger, it didn't spin freely enough that a slight push would cause it to rotate a full revolution or something like that. I have no idea how easy it should actually turn.
"I also retested the basic position in the MWB 11 and observed the VTG (Variable Turbine Geometry). It moves perfectly, approximately 1-1.5 cm up and down. Without the exhaust, the whistling sound of the turbocharger is very noticeable."

I'm completely at my wit's end right now. I have no idea what else I can do. Does anyone happen to have a dyno chart from a well-tuned AFN engine that I could use as a reference point?

Are the values for the injection quantity correct? I'm confused because they seem to be frequently capped. Or am I misunderstanding something? What about the smoke limit and the Dremo setting?

I hope someone can still help me.

Regards,
Holger.

So die Logs sind fertig. Okay, please provide the text you want me to translate from German to English. I will only provide the translation.

/viewtopic.php?t=16323

Quote:

Are the values for the injection quantity correct? I'm confused because they seem to be frequently capped. Or am I misunderstanding something? What about the smoke limit and the Dremo setting?

He's obviously running in a mode that limits exhaust emissions because without boost pressure, there's no air intake. However, I think the fuel injection volume is still high enough to actually produce the desired boost pressure. That's why I'm not saying the mass airflow sensor (MAF) is definitely defective.
Perhaps Ulf can provide more information on that.

Since the actuator system of the VTG is working correctly, it's likely that the problem lies with the charger itself. Therefore, I would like to ask again: where did this charger come from? Is it a new part, or was it sourced from a repair facility?

We've had threads about this before where external chargers weren't working properly...