VTG Valve Diagnosis: CBAB Unit Repair

Hi.

Before a colleague's CBAB (Control Box Assembly) receives a new VTG container:

Does anyone have data requests or ideas about what can be logged to provide an example of "this is how it breaks"?

I'll definitely make a video of the sound the can makes when it opens.

I'm thinking of using the "cloud" configuration, specifically N75/G581, as I have done with BMRs before.
(I still need to find the CR MWB for G581.)

Quickly, because:
The BorgWarner turbocharger belonging to a BorgWarner employee (what a coincidence!) will receive the new housing this Saturday.

We are the Borg, resistance is futile.

m;


The cloud at BMR:
[img]/download.php?id=5273[/img]

Ideally, the curve represented by %G581(%N75) would be a straight line.

I would say that the more widely the data points are spread out, the worse the control loop functions.

Best regards, Rainer.

dieselschrauber wrote:

Ideally, the curve from %G581(%N75) would be a straight line. I would say that the more widely the data points are spread out, the worse the control loop functions. Best regards, Rainer

Not quite!

The brake pressure, specifically the intentional creation of (unnecessary) boost pressure to assist with engine braking, is not reflected in all applications within the mass airflow sensor (MAF) system controlled by the N75 valve.
So, the N75 remains unchanged, even though the turbocharger is being engaged.

That will distort the line.

However, the image above is already quite close to a straight line, as it is clearly visible.
I also found a faulty BMR pressure sensor as part of the troubleshooting process.

Here's the first code review that I can work on in more detail.

BorgWarner is not entirely sure whether the rod length will be automatically adjusted or if it will still require manual measurement, evaluation, and adjustment of the rod.

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

Quote:

So, the N75 remains unchanged, even though the turbo IS being engaged.

Are you sure? In my case, the N75 duty cycle always showed the desired value, while what "boost pressure target" does is a completely different matter...

Do you have an example of that?

Quote:

Do you have an example of that?

Hmmph.

I'm pretty sure I saw it on a Seat Leon ASV.

It's like the "VTG brake" is being activated *after* the values from MWB 011 are read.

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

WOW.

VTG is dead... it's stuck at roughly 30%, seemingly unable to move.
Only when the vacuum hose is blocked does the path length decrease further to 11%.

And yet, the turbocharger still provides full boost pressure, but it's very subtle.
Errors in AI systems are not easily provoked.

Quote:

And yet, the turbo provides full boost pressure, but it's just very subtle.

...where an activation of around 30% is likely sufficient. What's so surprising about that?

My car can also reach high speeds with only half throttle -- it just takes a little longer .

Fix or replace the part first...

Sure, here's the translation of the text from German to English:

"Edit: Is the vacuum system really always airtight?"

Autoservice wrote:

Quote: And yet, the turbo delivers full boost pressure, but it's just very slow. ...where a stimulation level of around 30% is likely sufficient. What's so surprising about that?

Yes, completely unsurprising.
But I thought that 30% was still too little.

Autoservice wrote:

Fix or replace the part first...

Since anyway

Autoservice wrote:

edit: Is the vacuum system really always airtight?

I don't understand the question.

Do you want to know if we can rule out any general leaks?

To the extent that "yes," the can is definitely leaking.
It squeaks loudly, but becomes quiet when you hold something directly in front of the opening.

Quote:

I don't understand the question. Do you want to know if we can rule out general leaks?

Do you remember? Back then, I had a BMR (a type of diagnostic device), and the magnetic valve for the intake manifold switching was intermittently sticking, and the intake manifold switching system was leaking. Of course, everything seemed fine during testing. It's easy to get frustrated when you can't find the problem if you don't check the actuators separately... especially when you don't have time. That's why I now use a vacuum gauge in between for these kinds of tests.

While this might not directly relate to your problem (since errors have been found), it's still something to be aware of.