Intake Manifold Pressure: Golf 4 TDI 81kW

Hello,
I have a Golf 4 TDI, manufactured in 1998, with an 81 kW engine (engine code AHF). Recently, while driving on the highway, I noticed that at a speed of 170 km/h, the engine power decreased and the speed was limited to 140 km/h. After that, the car stopped accelerating. I took it to a VW workshop, and they read the error codes, which indicated a 'charge air pressure control differential' error. They told me that the problem could be either the turbocharger itself or the hoses.
Has anyone else experienced this exact error?
Who can help me?

Best regards,
Elias

Elias wrote:

They read the error code, and it indicated a vacuum leak in the intake manifold.

Did they invent a new error code, or were they just trying to mess with you?
Or perhaps you've mixed something up?
Okay, I'm ready. Please provide the German text you want me to translate.

Okay, so first of all, I spelled it correctly. What I should add is that the error occurs sporadically.
And secondly, I had it done at a VW workshop, and I personally read the report, so please...

Who can help me?

Elias wrote:

So, first of all, I wrote it correctly, and what I might add is that it still says that the error occurs sporadically... And secondly, I had it done at a VW workshop, and I read it myself, so please...

Okay, then I'll sign off here... I don't recognize "low pressure in the intake manifold" as an error message.

But you never stop learning: let's see what the others are writing .

@ elias:
I had the same problem, and it was solved by reattaching all the air hoses starting from the air filter. Sometimes they don't fit properly.

In my case, I also had a faulty relay (part number 109). I suspect that it was also responsible for the 'intermittent control difference; error code 575' that I was experiencing. I had the relay replaced by VW for 30 euros including parts - and since then, everything has been quiet.

some links:
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Wait until the error occurs again, and have the error codes read by a friendly mechanic.

I would also like to help, but I can only support what Ulf said. Which sensor measures the vacuum in the intake manifold of a TDI engine?

Could it be that there was a difference in pressure in the intake manifold or something similar?

Yes, I have to say I phrased it incorrectly. The actual error is called 'intake manifold pressure control differential'... (I've read it again).
Maybe now.
How exactly should I proceed?

Elias wrote:

How exactly should I proceed ???

1. Read articles on the subject -> common mistakes and VTG loaders.

2. If you understand, please check what's wrong with your engine.

Ulf, thank you, but I'm not very familiar with that. You'll have to explain it better to me, e.g.
What is a VTG loader?

Elias wrote:

What is a VTG loader?

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
Here's a very important tip: The search function is full of useful information for beginners...

Ulf, you friend of humanity!

Others might have already given up and closed down a long time ago.

It's something that needs to be said from time to time, otherwise you lose the motivation, right??
And the forum would be poorer because of it.

@Elias: Searching and learning is fun with TDI, but be careful: you might not be able to stop yourself from continuing...

Greetings, Klaus.

Klausel wrote:

Others might have already given up and closed down a long time ago.

I had thought about that too, but sometimes I just slip out of that mindset...

Yes, I must say I phrased it incorrectly; the exact error is 'intake manifold pressure regulation differential'.... (I've read it again).
Maybe now.
How exactly should I proceed?

I also had this problem. Please check all the thin hoses that run from the air filter for brittleness, proper seating, kinks, etc.
'In my case, a hose was loose... it's been quiet for 12 months now...'

Hello,
I just went to VW and told them to replace the turbocharger boost valve. They test-installed a new one.
That wasn't it.
Then they thoroughly inspected the hoses and everything was okay.
Next, they replaced the exhaust gas recirculation valve because it was leaking.
The error was still there.
'Measurement block, driving, what's next? Did you find anything there?'
Okay, so I paid 204 euros and picked up the car.
The expert is 100% sure that it's the turbocharger.
Do you have any tips or suggestions on how I can get a turbocharger at a low price?

Hi,

Is the VTG adjustment easy to operate?

Best regards,

Jan.

He means.