Performance Issues at High Speed: Error 575

Hello,

I've been looking into the forum extensively over the past few weeks, but I can't seem to figure out what's causing the problem with my Passat.

Fault code: 00575 - Intercooler pressure control difference occasionally.
Engine code: AFN
Engine power: 81 kW (1.9 TDI).

The problem occurred every summer when driving above 140 km/h. Suddenly, there would be a noticeable jolt, and the engine would switch to emergency mode (and the error memory would contain the aforementioned error).

The problem starts occurring at speeds as low as 120 km/h in the winter.

It's also noticeable that this issue only occurs when the engine is fully warmed up (i.e., after about 0.30 to 1.00 hours of driving).

Therefore, I suspect it might also be related to temperature; that is, hoses could be expanding due to heat, and if there's any porosity, air might be leaking out. I've examined the hoses roughly, but haven't noticed anything.

'It's also noticeable that I now consistently have full power at the 'throttle'. This means that even when it's cold, it pulls very well (before, it took a little while to warm up). I suspect it's running with relatively high boost pressure and can't compensate for it - and that's what's causing the error. In fact, I've even managed to put it into limp mode while driving in city traffic (at high RPM).'

Today, I tested the resistance of the exhaust gas recirculation valve (it's approximately 13-16 ohms – the same values were also measured for the boost control solenoid valve).
'I'm getting a voltage of approximately 6V at the connectors when the ignition is on (I thought it should be 12V, so I tested other connectors as well, and everywhere it's 6V; with just the ignition on, the battery shows 12V; with the engine running, the battery shows 14V, which seems correct for the battery).'

What I also noticed is that there's a hose that seems quite porous, but I haven't been able to find out what it's used for.
http://www.seismicdesign.de/pub/Schlauch.jpg
(Could this contribute to the error I mentioned?)


Please help me... I'm slowly going crazy!

Thanks.

Greetings.

You have power loss in an engine with VTG.

You should be able to find so much information about these terms that any further text becomes unnecessary.

And if you already have the error code, you can also search for it directly.

Please search first, then ask.

Thank you.
Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Hello,
Check if the VTG adjustment is working properly!
Best regards,
Günther.

The hose where the arrow ends is the crankcase ventilation hose.

The movement of the pistons changes the pressure inside the crankcase, which is then released back into the intake manifold.

This shouldn't be related to error code 00575.

It's more likely the thin hose with the textile reinforcement around it, which is also visible in the picture, and which connects to the vacuum chamber.

Please also read the technical article about servo pneumatics for motors with type designation VP37.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

It's more likely the thin hose with the textile covering around it, which is also visible in the picture, and that ends in the vacuum chamber.


So, that basically means the hose might be having issues. I need to take a closer look at the VTG linkage tomorrow (Is it possible to specify this further in the logs?).

Okay, so the rod you're talking about is essentially connected to the hose that goes into the vacuum chamber, which would be located below it.

Sure, you can definitely see something in the logs.

The 00575 has a reason, and that reason can certainly be seen.

Please log "log mal 003-008-011" and make the CSV file available for download, then we might be able to help you more specifically.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

This is what your turbo looks like:

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html

Quote:

Is it possible to specify more details in the logs?

Ja klar, Soll und Ist des Ladedruckes (Block 11) über ein paar volle Beschleunigungen im 3. Gang von 1.400/min bis 4.000/min mitloggen. See the technical article.

//edit: Dieselmartin was faster. Yes, 003 and 008 are also useful .

Okay, so... this is a few months old, but the error occurred then as well.

I've marked the entire process with the accelerator pedal: that is, the most interesting measurement is at the end, where the RPM increases nicely. After I experienced the emergency mode, I brought the engine back to idle (which marks the end of the measurement).

http://www.seismicdesign.de/pub/LOG-01-003-011-xxx.CSV

And if this might also be helpful (because I couldn't figure out the error).
http://www.seismicdesign.de/pub/LOG-01-003-011-OK.CSV

Best regards,

Clearly, the boost pressure is sometimes significantly above the target value, which explains the limp-home mode. Please refer to the technical article for troubleshooting the VTG (variable geometry turbine).

"//edit: In the second log, the target pressure was only reached at approximately 3,000 RPM. The variable geometry turbocharger (VTG) seemed to be lagging behind. The engine likely felt sluggish in the lower RPM range."

So, I'm sure the motor didn't feel any different (I couldn't detect any difference).

Okay, so I took a closer look at the whole thing today. I tried manually moving the VTG linkage (as described in the technical articles), but it seemed impossible to move it. I didn't disconnect any hoses and only attempted this with the engine off. The main problem is that I can't even see the linkage (see the picture posted above). It's quite difficult to access. At a certain angle, I could barely make out the threads, but I couldn't really detect any difference between the engine being on or off (the rod should move to a different position in that case). This might also be due to the very limited visibility.

'Has anyone here had experience with a Passat 35i facelift? I'm wondering how to best access the VTG linkage, as it seems quite tightly packed.'

The hose from this container leads to the magnetic valve for turbocharger pressure regulation. I noticed that before the hose ends at this valve, it's connected to a small piece of hose – essentially forming a kind of bridge before it reaches the valve (is this normal?).

I'll do the 'injection test' tomorrow and hopefully get closer to understanding everything.

Best regards,

Sure:
Okay, grab a syringe and a mirror, then get a headlamp. You might look like a doctor, but it should be relatively easy to achieve a result (either "the VTG is permanently stuck" or "something else is the problem").

m;

P.S. I specifically bought a small hand mirror from the cosmetics section to use when working on my car .

Baked on...? Do you mean from soot?

Thank you, the idea with the handheld mirror is great; I will try it!
Is that thing with the hose bridge normal? (from the previous post)


Regards

After coming in today to analyze the 'VTG rods,' here are my results:

First, here are the pictures I took:
http://www.seismicdesign.de/pub/MotorAN.jpg
http://www.seismicdesign.de/pub/MotorAUS.jpg

Here are a few movies I watched while administering the 50ml injection.
http://www.seismicdesign.de/pub/Spritze.avi
http://www.seismicdesign.de/pub/Alternativ2.avi
http://www.seismicdesign.de/pub/Alternativ3.avi

The articles mentioned a lift of about 1 cm, but it seemed smaller to me, more like 5-7 mm (see photos and videos).

Does anyone have any idea how I can figure out this error or what it might be?

With a request for assistance.

Greetings.

sethmuc wrote:

The articles mentioned a lift of about 1 cm. However, the lift seemed a bit smaller to me, more like 5-7 mm (see photos and videos). Does anyone have any idea how I can now figure out the error or what it might be?

If the rod moves gradually or jerkily when the injector is operated, it is likely that the valve guide is clogged with soot or deposits.
Or warped due to excessively high exhaust temperatures after a tuning modification.
A common side effect is often a "blurry" minimum or maximum stop, where the overtravel protection device (VTG) can become partially jammed.

Or if the can itself is clogged, disassemble it and repeat the injection test.

If someone has adjusted the VTG rod, the insufficient lifting height could be due to that.

Please check all of this.

If the rod moves gradually/jerkyly when the syringe is operated (.
It actually seemed to be working quite smoothly (meaning the positions within this hub were easy to reach).

Or warped due to excessively high exhaust temperatures after a tuning modification.
Nothing was tuned there.

Nothing was adjusted on the rod either (I'm very sure of that).
However, there was a sound coming from the can, like something metallic or spring-like inside (making a slight squeaking noise, similar to an old bed), when it was being dispensed. It could have also been from the dispenser itself, but I suspect it came from the can.