TDI AHU; 00575 - Intake manifold pressure regulation differential

Hello.
"Recently, I've been having a problem with my Golf. When driving on the highway, it goes into limp mode around 3000 RPM in 5th gear, and then I can barely reach speeds above 130 km/h."

Under normal conditions, power and torque are present, and it behaves as expected.
Even when accelerating in the first or second gear, there are no issues.

So far, I have checked the following.

Measurement of boost pressure matches the ambient pressure when the engine is stationary.
N75 can be triggered with a tester and also clicks.
The hoses connecting to/from the turbocharger (TL) and the N75 valve appear to be visually fine.


Can someone tell me what I should check first, and what should be logged during a test run?

Thank you.

Hi,
Please check the hose leading to the pressure sensor in the control unit. Just like here, my post is almost at the end of the thread.
/viewtopic.php?t=16310&highlight=regeldifferenz&start=32
hg
Herbert.

Hello Herbert.
Thank you very much.

Do you mean:

Contaminants in the boost pressure sensor can affect the pressure measurement to such an extent that the control unit (ECU) dynamically adjusts a value that is significantly different from the mass airflow sensor (MAF) value.

Should I just blow through the hose?

Thank you.

Quote:

Should I just blow through the hose?

Exactly. Simply disconnect it from the engine control unit (ECU) and press the accelerator.
hg
Herbert.

Hello.
Okay, I'll report back in the next few days.
But what ultimately happens to the oil that ends up inside the sensor?
Will that become a problem sooner or later?

bindpe wrote:

Hello. Okay, I'll report back in the next few days. But what ultimately happens to the oil that ends up inside the sensor? Will that be a problem, sooner or later?

It's too little and not thick enough to solve the problems.

There's also a hose in the control unit; open it up and take a look.

Rüdi wrote:

There's also a hose in the control unit, open it up and take a look

.
But be careful, what goes up must come down. If the control unit is difficult to open, it's better to simply pour brake cleaner into the charge pressure connection of the control unit and let it drip out downwards.

Hello.
Sure, no problem.

Sure, here's the translation:

"One more question, I have a replacement control unit."
If clearing the hose doesn't help, I would try installing the other one as a test.

Do I need to have this programmed, or is the login PIN for the immobilizer required?

The hose is also prone to breaking.

I've also had MSG that was completely saturated with oil.

bindpe wrote:

Hello. Sure, no problem. Sure, here's the translation: "One more question, I have a replacement control unit." If clearing the hose doesn't help, I would try installing the other one as a test. Do I need to have this programmed, or is the login PIN for the immobilizer required for this?

http://wiki.ross-tech.com/wiki/index.php/Immobilizer

Hello.
Today, I removed the engine control unit and externally applied a pressure of 2 bar to the sensor connector.
There was a noticeable hissing sound coming from the control unit, which likely indicates a ruptured hose.
Unfortunately, the screws were so corroded that I couldn't get them loose.

Therefore, I installed my replacement unit (new), and it's working fine. It also didn't leak during the pressure test.
Then I also replaced the hose that goes to the intake manifold.

Unfortunately, the error is still there ;( What else can I do?

Thank you very much.

Hello,

I would use VCDS to check if the turbocharger boost pressure is too high or too low. See.
/newuser.php


Sure, here's the translation:

"LG" translates to "Best regards" or "Sincerely" in English.

Hello.
Today, I performed two measurements as described in the repair manual. First, I did a full-throttle acceleration test in 2nd and 3rd gear. Then, I repeated the same test with the N75 valve disconnected.
According to the repair manual, with the N75 valve disconnected, the boost pressure should be approximately 1.65 bar (absolute) at 3000-4000 RPM, and with the valve connected, it should be approximately 2 bar (absolute).
Based on the measurements, that seems to fit quite well. Unfortunately, I wasn't able to reach speeds of over 3500 RPM on my track.

I only have MWB 8 and 10 with me right now.
Unfortunately, I only realized afterward that MWB 11 also includes the target pressure and key travel distance.

What else can I do? Okay, let's run the entire process again using MWB 11, and then try to reproduce the error.

Thank you.

Whether the value is too high or too low is determined by comparing the target value with the actual value in the respective operating condition...

I find it baffling that a log should only provide information based on one of those two values.

Okay, so compare the setpoint and the actual value!

Good morning.
Thank you for the information.
I will repeat the measurement, as I said.
I initially took the target values from the REP guideline.