Passat 3BG BDH Engine: Check Engine Light/Limp Mode

Hello everyone,

My father's V6 TDI engine is having problems.

Suddenly, while driving, a loss of power occurred, the check engine light illuminated, and the message "Emission system fault" appeared on the driver information system, followed by the engine entering limp mode.

The error memory displayed the following:

Exhaust gas recirculation: Control limit exceeded, maximum value.
Intake manifold pressure: Regulation limit exceeded.


I then removed the AGR valve, and it looks clean and is working properly. The diaphragm in the pressure sensor is also fine.

What was also noticeable was that when the engine was revved up, there was a brief, rather rough diesel-like sound, which I couldn't identify.

What can trigger an intake manifold pressure error?

Please initiate an automatic scan.

I also tried that, but it only showed the driver's side crash sensor in addition to the other information, which I was already aware of.

You shouldn't 'try' it, you should actually do it and upload it.

Here's the log, I'm curious to see what it says...

Another thing that was noticeable: when the engine revs up, there's a brief, rather rough diesel-like sound, which I couldn't identify.

Aggressive hammering? Are you dynamically checking the injection start?

Yep, that's kind of what it feels/sounds like.

Are there no "standard defects" that could explain the problems/errors I'm experiencing?

Well, maybe the spray nozzle.

I don't understand what the intake manifold pressure has to do with it.

How can I check this? Maybe check the start of the injection?

What was also noticed is that, according to the data displayed below, the boost pressure is always too low at lower engine speeds; it only reaches the target range at around 3000 RPM.

Okay, I'm ready. Please provide the German text you want me to translate.

You can check the injection settings in the basic settings.
Not enough fuel, insufficient/delayed boost pressure = no power.

Check the control unit on the pump, as the VP 44 is known to have issues.

Greetings.

Thank you for the tip.

I just checked the VTG (Vehicle Traction Gauge) readings, and they are working perfectly.

However, I think I now know the real reason for the intake manifold control error: My father has that awful tuning box (which was sold to him by a so-called "friendly" dealer), and I completely forgot about it .
No wonder, then, that "too little" boost pressure appears in the measurement block .

Today, the car started normally at first, I drove it for about half an hour, then the limp mode came back, along with the emissions warning and the check engine light. I then logged the activity of the EGR valve, and sure enough: it's sticking occasionally! So, I'll start by checking the vacuum hose and the solenoid valve, and the electrical connection, and then I'll take a closer look at the valve itself.