AFN Performance Issues: Troubleshooting Guide

Hello.

I've been driving a Passat with an AFN engine and a 4-speed automatic transmission for a few days now.
The first problem that arises is a significant performance weakness.
Miserable acceleration and a top speed of 160-165 km/h.

No errors in the memory, but at idle, the mass airflow sensor (MAF) reading is approximately 225 mg/H.
and does not exceed 510 mg/H (should be 850-1100 at full load) according to the VAG-COM measuring block 10, field 1.
After cleaning with brake cleaner until it reached approximately 600 mg/H, there was no noticeable increase in performance, which is still far too low.

Based on what I've read here, I suspect it might be the mass airflow sensor (MAF), but could someone confirm that? Also, what else should I check? A MAF sensor isn't cheap.
Sure, here's the translation:

"Thank you in advance."

Voss.

voss wrote:

No errors in the memory, but at idle, the mass airflow sensor (MAF) reads approximately 225 mg/H and does not exceed 510 mg/H (should be 850-1100 at full load). Based on what I've read here, I suspect it's the mass airflow sensor (MAF), but could someone confirm that? Also, what else should I check? A MAF sensor isn't cheap.

Hi.

If you want to build it from scratch:
http://www.dieselschrauber.de/vptdifehler.html

If I were in your position, I would check the turbocharger boost pressure next.

Hello.

First of all, thank you for your reply.
I measured the boost pressure in block 10, fields 2 and 3, and the actual value is following the target value.
Maximum difference between the actual value ("is") and the target value ("should") is approximately 100 millibars. In most cases, the actual value is higher than the target value.
Is that normal?
Otherwise, it's fine for me.
Should I get a new LLM now? It seems like I have no other choice.

Regards,
Voss.

voss wrote:

I measured the boost pressure in block 10, fields 2 and 3, and the actual value is rapidly approaching the target value. Maximum difference between the actual value ("is") and the target value ("should be") is approximately 100 mbar. In most cases, the actual value should be greater than the target value. Is that normal?

Hi.

Okay, that's fine.

Quote:

Should I get a new LLM now?? I think there's nothing else I can do.

In most cases like this, a healthy LMM would likely resolve the problem.
But sometimes, the devil is really in the details...

Hello.

Today, I wanted to measure the air mass again and noticed that the value is consistently at 550.
and there's also an error in memory – it's likely an LMM issue.

"Tomorrow, if I have time, I'll pick it up from DC."
And another question: My LMM (likely referring to a mass airflow sensor) has the part numbers "F00C2G2004" and "865091B". Would the DC part number "A 611 094 00 48" be a suitable replacement?

Regards,
Voss.

Hi Voss,

Before you invest, try 'Georg's' trick (from 'Georg_G'). It really works well, and you'll know for sure if it's the real deal.

Please provide the text you would like me to translate from German to English. I need the text itself to be able to translate it.
/viewtopic.php?t=954&highlight=diode+lmm