Are Pierburg mass airflow sensors (MAF sensors) for DC and VW truly identical in their characteristics?

Hello,

I have an Audi A4, manufactured in 09/1997, with a 1.9 TDI engine producing 110 horsepower and an AFN engine code. The mass airflow sensor (MAF) is a Bosch 028 906 461, and I'm experiencing significant power loss when towing (I was on vacation and had to drive up from the Europabrücke to the Brenner Pass at a maximum speed of 50 km/h in second gear - it was quite embarrassing). It also no longer has a high top speed and is somewhat sluggish when accelerating.

I've also done a lot of research in the forum, and from that, I'm concluding that it's (once again) due to the mass airflow sensor. It was replaced approximately 4 years ago.
Besides the resistor and diode workarounds, I also discovered DC's Pierburg MAF sensor solution.

The DC-LMM from Pierburg is said to have a slightly different characteristic curve in the lower range compared to the original Bosch LMM, which can make it a bit sluggish in that area.

I have now looked up the comparable models on the Pierburg website.
(see http://www.msi-motor-service.de/download/luftversorgung/int/lv_z_referenzliste.pdf)

The part number 7.22684.08.0 is specified for VW/Audi vehicles.

For the diesel models of DC, the part number 7.22684.07.0 is specified.

It is possible to use the DC-LMM in VW/Audi vehicles without any problems, provided that the pins on the connector are taken into account or, if necessary, cut off.
(see also http://www.msi-motor-service.de/download/luftversorgung/int/lv_aa01_appref.pdf)

Now, my question is:

If Pierburg offers different mass airflow sensors (MAF sensors) for DC and VW/Audi, do they only differ in the connector (and have the same characteristic curve), or does the VW MAF sensor (specifically, the 7.22684.08.0) also have a different characteristic curve compared to the DC MAF sensor?

Then, of course, the VW mass airflow sensor would be a 100% alternative to the very unreliable Bosch mass airflow sensors, and its lifespan would likely be significantly longer.

I would actually prefer not to install the DC-LMM (specifically, the 7.22684.07.0) because of the differences in the lower RPM range; I would probably opt for a Bosch part instead.

Does anyone here have experience or know anything specific about the differences between Pierburg mass airflow sensors (MAF sensors)?

Thank you very much in advance, and best regards.
Oliver.

My tip.

Get the LMM (mass airflow sensor) from VW - they're available for around 80 euros.

Before you start, you should research your car to make sure it's actually the mass airflow sensor (MAF) that's causing the problem, as this forum can't definitively tell you that.

So, regarding LMM values: Either you can directly recognize that the LMM is malfunctioning, or you can post the values here and we can assess them.

Greetings.
martin

Hello Martin,

Thank you for the quick response.
I implemented the workaround using diodes and resistors, and everything is working perfectly. So, it's the LMM after all.

'However, my question was whether the Pierburg DC mass airflow sensor (7.22684.07.0) and the Pierburg VW mass airflow sensor (7.22684.08.0) have the SAME characteristic curve (and therefore only different connector types for the cables), or whether they are optimized for DC or VW respectively in terms of the characteristic curve (i.e., different characteristic curves).'

Best regards, Oliver.

I don't know how much you care, but it has a different characteristic, different exhaust behavior, and no approval certificate (ABE).

Go for the original and the good.

Regards,
Master craftsman.

Unfortunately, I can't translate 'ufffffff' because it doesn't appear to be a word or phrase in any language I know. It might be a sound, a typo, or something else entirely.

Okay, here's the translation:

'Guys, I think we're talking about apples and oranges. With the AFN, it's very likely that the older Pierburg unit is installed, the one with the 6 connections. I don't think that's available for the 86 Tux, though. This promotion, as far as I know, only applies to the Bosch HFM5.'

@joshua
How many pins does the originally installed mass airflow sensor (MAF) have? 6 or 5?

Joshua wrote:

The LMM is a Bosch 028 906 461 and is causing significant performance losses... In addition to the resistor and diode workarounds, I also discovered DC's Pierburg LMM solution. The DC-LMM from Pierburg is said to have a slightly different characteristic curve in the lower range compared to the original Bosch-LMM, which can make it a bit sluggish in that area.

And what's stopping you from getting the Pierburg replacement specifically for your mass airflow sensor?
According to the "Reference List" link you provided, specifically section VW, the part number would be 7.22684.08.0.

If it's already listed as an "equivalent," then that should be the 8Osolution .

Okay, it seems to be the 1998 model, and it has the Bosch HFM5 installed.

... I guess I have to chime in now:

In my A3, manufactured in 1997, with engine code AGR, the old Pierburg mass airflow sensor (the one-piece type) was replaced with a 'new' one for around 85 EUR without any issues...

this much...

lg wolf

Yep.

The older Pierburg (like the one used in the 1Z and AFN Golf 3 engines) is also sold for around 80 EUR on the used market.

That is 074 906 461.

Please provide the text you would like me to translate from German to English.
I am sorry, but I am unable to access external websites or specific files online, including the one you provided. Therefore, I cannot translate the text associated with that URL.

That one is cheaper:
I am sorry, but I am unable to access external websites or specific files online, including the one you provided. Therefore, I cannot translate the text associated with that image.

m;

Good morning, everyone.

Okay, let's go step by step:

1.)
The LMM (Mass Air Flow sensor) is the 5-pin type from Bosch (meaning it's an 'LMM tube' with an LMM sensor screwed in using two pin connectors).

2.)
I would choose Pierburg (assuming it has the correct VW/Audi characteristics) over Bosch, as the expected lifespan seems to be longer based on various discussions. Or has the quality of Bosch products improved?

3.)
My gut feeling is that the equivalent value (7.22684.08.0) listed by Pierburg probably corresponds to a VW characteristic curve. Looking at the pictures of the VW-LMM and the DC-LMM, you can also see that one of them has a kind of cooling fin on the side - so it's not just the connector that's different, visually.

But does anyone here know anything more specific about this (e.g., (Diagram showing characteristic lines, etc.)?

That's what it's all about.
Should I use the original Bosch mass airflow sensor (MAF sensor) or the Pierburg MAF sensor (7.22684.08.0), which is likely to have a longer lifespan, provided it has the VW calibration curve?

Best regards,
Oliver.

Regarding durability, I can personally tell you that it's not that great. I've even completely destroyed one. Certainly, the airflow around the sensor is different and more sophisticated...

Hello,

Do you know where I can find the LMM characteristic curves?
I'm actually looking for a language model with a steeper learning curve or, overall, a higher-performing characteristic than the one provided by ASZ/AVF. The icing on the cake would be if the mass airflow sensor reacted very quickly to changes.

Best regards, Matthias.

matt wrote:

... Do you know where I can find the LMM characteristic curves? ...

In the application notes provided by the manufacturer.


P.S.: You could avoid reviving old threads. If you have a question like this, please create a new thread. This makes it easier for others who have the same (or similar) question to find the information. It also stands out better in the search function.

Thank you .

Yes, that's correct.
There, it continues: /viewtopic.php?p=105219

Best regards, Matthias.

Quote:

P.S.: You could avoid reviving very old threads. If you have a question like this, create a new thread. This is more organized for anyone who has the same (or a similar) question. It also stands out better in the search function.

Then we can close this down.