00575: Another Occurrence? Find Out Now!

Hello,
I've been sifting through various posts about the 00575 part for days now, but unfortunately, I haven't found anything suitable yet. I've proudly owned an Audi 80 1.9 TDI (1Z) from 1994 since September.
It started last August when we rode our motorcycles on the highway for 200 km and experienced a typical drop in performance, making it difficult to reach speeds above 110-120 km/h. When we arrived, we went to ATU (an automotive service chain) to have the error codes read out (we didn't know any good workshops there, and I hadn't started working on it yet). The result was an incorrect intake manifold pressure reading. The guy at ATU immediately said, based on what he saw, "It's probably the mass airflow sensor." My dad, of course, believed him and had it replaced right away (at that time, he still owned the motorcycle...).
After that, we were on the highway without our bikes, and he ran perfectly well until 170 kilometers, then came the exit.
After a week, I drove the 200 km back home with the bike on the roof again, and it was already at 120 (presumably referring to speed or some other measurement).
"So, we took the box to a mechanic around the corner, and thanks to the actuator diagnostics, he found a faulty pressure sensor, a defective solenoid valve, and a damaged pressure hose. He replaced them, and since then, we haven't had any more issues with the bike on the roof again. It runs wonderfully now, but if you drive at 100 to 110 km/h in 5th gear for a longer period under full throttle (like going up a steep hill on a country road), there's a slight jerk, and the speed drops. Then it doesn't pull anymore after cresting the hill. You have to completely release the accelerator pedal again, and then it starts working again."
And every time it happened again, I got the same error code (575) in the diagnostic memory. I then did a test drive with my laptop on the passenger seat, accelerating from a standstill to 100 km/h in 3rd, 4th, and 5th gear on the country road.
While doing this, I noticed that the boost pressure is always BELOW the target value when accelerating fully, and it's always ABOVE the target value when coasting.
Most of the posts I found describe a boost pressure that is ABOVE the target value.
I still wanted to test the pressure sensor, so I had my neighbor rev up his TDI engine and watched the linkage of the pressure sensor, and it only moved a few millimeters towards the end of the rev range. Then I removed the pressure sensor and checked if the wastegate was stuck, but it moves almost without any resistance. How much movement should there be?
And most importantly: What could the error be?
Sorry for the long text... I hope someone is willing to wade through it and can help me.
Here's the log from the test drive:
http://www.markus-kaindl.com/audi/09-05-07_schleh.xls

Thanks to everyone who managed to get through it.

kaindl

Okay, I see that, I was providing too much text again; I should restrain myself next time. Sorry.
Okay, in short:
My Audi 80 1.9 TDI (1Z), manufactured in 1994, experiences a noticeable and sudden loss of power when going uphill at approximately 100 km/h in 5th gear (unfortunately, I don't have a tachometer).
The LMM (mass airflow sensor), pressure sensor, and solenoid valve were replaced in August.
I once did a test run on a flat country road, accelerating from a standstill in 3rd, 4th, and 5th gear up to 110 km/h. The data is attached as an .xls file with a diagram.
http://www.markus-kaindl.com/audi/09-05-07_schleh.xls
I hope someone can give me some tips on how to find the error.

Best regards, Kaindl.

Oh yeah... I feel like it's emitting too much smoke and soot, but it might also be my imagination .

It would have been helpful if you had also logged the air mass data.

The boost pressure is far too low, which is probably why the system will eventually go into emergency mode under prolonged full load.

If it's making a hissing sound, I would initially suspect that the intercooler piping is completely leaking.

'@Malte, he did, but you had to look a little bit.'

What one sees:

- Air mass continuously below the target air mass value.
-During acceleration, the boost pressure control valve opens to 39.4% (maximum value?).
-Very slow boost pressure build-up, target boost pressure is never reached.
-The engine operates continuously within the smoke reduction zone when a load demand is present.

My idea:
The turbo isn't doing what it's supposed to do!

According to the measurements, the charge air cooler system should be airtight (the target mass airflow is not being achieved).

Perhaps there's still something stuck in the vacuum sensor or the bypass, and that might be the root of the problem.
In extreme cases, the turbocharger might have reached the end of its lifespan. How many miles has it been driven?

If the mass airflow sensor (MAF) was replaced at ATU, it's a good idea to re-check the diode test. You don't want them to have installed a faulty unit that causes incorrect air mass readings.


Best regards, Jochen.

Hello,
I logged the air mass data, and for each set of measurements, I created a separate sheet in Excel to keep things organized.
I just put up a diagram of the air mass for group three and noticed that the air mass jumps from too much to too little when switching between full throttle and no gas.
If that confirms your suspicion that the printing head is leaking, how do you best locate the leak?
Best regards, Kaindl.

Quote:

I also logged the air mass data; I created a separate sheet in Excel for each set of measurements, just to keep things organized.

No, that's exactly what makes it confusing.

When evaluating the 003-008-011 data, it's *always* about how these elements interact and fit together (or don't fit together, because something is broken).
To be able to tell if they are doing the same thing, such as rising or falling at the same time, or behaving in a noticeable way, you need to have them directly next to each other.

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

Quote:

"@Malte, he did, but you had to look a little bit."

Oh yes, it's about 30°C in my apartment .

So, the air mass is constantly too low, which contradicts the theory of a leaky intercooler system. (Unless a faulty or cheap Mass Air Flow sensor (MAF) was installed at ATU ).

So, the turbocharger isn't actually producing any pressure. We need to check the N75 valve and the wastegate with its pressure sensor again.

I would try bypassing the pneumatic system by directly connecting the compressor side to the pressure reservoir. Then, I'd perform a test run. If the boost pressure stabilizes quickly and settles around 1500 mbar, that indicates the wastegate is likely functioning correctly.

Otherwise, continue to systematically review the relevant articles here.

The erratic jumps in the 011/4 data show that the EDC is trying to control the pressure, but it's completely failing.

There's something wrong with the turbocharger and/or its control system (pressure hoses).

Test the wastegate Injector test.
Test the N75 valve / temporarily replace it for testing purposes.
worst case: New turbocharger needed.

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

Does this tractor have a mass airflow sensor (MAF) or not?

So, are you talking about scales or measuring devices?

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

Hello,
It has a mass airflow sensor. It was replaced last August.
Best regards, Kaindl.

Quote:

Sorry, I didn't know that the measurements need to be next to each other; I'll remember that for next time. If I manage to do it tonight, I'll properly format the Excel file; otherwise, I'll do it on Thursday. "This weekend, I removed the wastegate actuator to test it." It moves very easily, but unfortunately I don't know how far it should move... maybe it doesn't go all the way anymore? How much should the lever move? Is the 2.N75 solenoid valve for the pressure sensor, am I remembering that correctly? 3. How do I perform a pressure test (using a syringe)? "I've read a bit about diode testing, but I can't find any specific information on how it works. What specifications should the diode have for this test? And which pins should I connect it to?" My Audi now has 220,000 km on the odometer, and to my knowledge, this is the first turbo it's had. Thanks in advance for your efforts with my messed-up logic. best regards, kaindl

'This weekend, I removed the wastegate actuator to test it.'
It's very easy to move, but unfortunately, I don't know how far it should be moved... maybe it doesn't go all the way anymore? How much should the lever move?
What was easier to move: the can or the lever on the turbocharger?
If leverage -> okay!
If 'Dose' -> Error found!
The container is quite difficult to move normally.
2.N75 is the solenoid valve for the pressure sensor, do I remember that correctly?
Yes.
3. Injection test, how do I do it?
Syringes with a 200ml capacity (suitable for horses, pigs, and cattle - available from your local veterinarian).
connect to the hose that runs from the N75 valve to the pressure sensor and apply pressure. The wastegate mechanism should then...
to move.

Best regards,
Rudi

The lever on the turbo moved easily, but the linkage from the canister didn't. However, I once read that the lever shouldn't be too easy to move either... and how far should it be able to rotate?
Best regards, Kaindl.

Quote:

Okay, so yesterday I bypassed the N75, but unfortunately, the boost pressure still didn't settle at 1500 mbar. Okay, I'm going to check the hose for the sender on the control unit. First, I searched for the control unit itself, and I think I found it, along with the associated wiring harness. http://markus-kaindl.com/audi/steuergeraet.JPG I immediately noticed that the hose, where the red arrow is pointing, is just loosely attached and doesn't have a clamp or anything like that holding it in place. Is this normal? Is this the "vacuum pressure sensor"? best regards, kaindl

Hello,
After unfortunately still not finding the error, I finally received a log today while the error is occurring.

http://www.markus-kaindl.com/audi/20-06-07_Irschenberg.xls

I've included the entire trip, from the parking lot to the gas station, because I don't know how much of the data before and after is relevant. In line 112, there's a marker indicating where the interruption occurred.

Situation: A highway on a mountain road, with an incline of approximately 7%. Initially, free flow driving at around 130 km/h, then a speed limit of 120 km/h, slightly uphill, followed by another speed limit of 100 km/h, with a 7% incline.
I was driving in 5th gear, speedometer just above 100 km/h, and after the engine cut out, I shifted to 4th gear at some point to get moving again.

I hope this log will help narrow down the source of the error.

Best regards, Kaindl.

Hello,

Maybe someone here can give me a tip.

The error occurs when I press the accelerator pedal quite hard between 2000 and 3000 rpm.

00575 - Intake manifold pressure.
17-10 - Control Difference - Intermittent

I once logged data from modules 011 and 003 using VAG-COM.
Unfortunately, it was a long drive with quite a bit of traffic. Around 1200 seconds (20 minutes), there wasn't much happening (congestion and downhill). At 1200 seconds, I could accelerate a little, and the turbocharger pressure increased. At 1700 seconds, during a brief acceleration, there was still some boost pressure. However, shortly after 1800 seconds, the turbocharger pressure no longer increases, and the emergency mode starts.

I have the VAG-COM log file on Rapidshare.

What I have checked:
Hoses checked, N75 actuator diagnosed and VTR tested with a syringe -> all appear to be okay. The EGR is also functioning correctly (actuator diagnosis performed at idle, and data was read from both the main system and port 011 simultaneously).


I'm wondering if the control unit might be malfunctioning (turbocharger pressure sensor). The hose is fine.

Thanks for any advice. As a hobbyist who likes to tinker with things, I'm a bit lost now.

Rainer.

"Sorry, I'm new to this forum. I just realized there's a section for log files. I posted my log file with the error code 00575."

/viewtopic.php?p=113688#113688

Rainer.

I've taken a brief look, but the log seems rather unusable. Please read the posts about creating the log, and then please take another look.