Unlikely Signal 16485-LMM: Log File Analysis Needed

Hello everyone!

I drive a Touran 1.9 TDI with engine code AVQ.

"Exhaust system workshop" message appears repeatedly (sometimes after 2 km, sometimes after 400 km), and VCDS reports:

Code:

Adresse 01: Motor       Labeldatei: RKS\03G-906-016-BKC.lbl    Steuergerät-Teilenummer: 03G 906 016 A    HW: 028 101 073 1   Bauteil und/oder Version: R4 1,9L EDC G000SG  5185                  Codierung: 0000072             Betriebsnummer: WSC 01324 785 00200                       VCID: 2166B723814F 1 Fehler gefunden: 16485 - Luftmassenmesser (G70): unplausibles Signal             P0101 - 000 -  -              Umgebungsbedingungen:                     Drehzahl: 1764 /min                     Drehmoment: 0.0 Nm                     Geschwindigkeit: 77.0 km/h                     Last: 0.0 %                     Tastverhältnis: 96.8 %                     Binärwert: 00101000                     Luftmasse/Hub: 245.0 mg/H                     Luftmasse/Hub: 245.0 mg/H Readiness: 0 0 1 1 0 Mittwoch,09,März,2011,16:39:16:64513 VCDS Version: RKS 10.6.3 Datenstand: 20101206

Symptoms:
Very hesitant acceleration; the turbo doesn't seem to kick in until around 2300 RPM. The maximum speed is no longer reached as it used to be (on the same section of highway, it's now 160 km/h instead of 180 km/h).

The error is always the same.

The mass airflow sensor (MAF) was replaced, and during the process, any loose hoses in the intake manifold were also reattached.
-> The error occurred again.

The cylinder head cover has been opened, and the sealing rivets for the rocker arm shaft have been installed.
-> The error occurred again.

Right now, I'm at a loss, and so is my trusted mechanic. The suspicions are leaning towards the PD unit(s) or the turbocharger.

I've read through many forum threads and, based on the information I found, I performed two "test drives" and logged the data from sensors 8, 10, and 11. Once, the warning light was on, then the error was cleared, and the measurements were taken again.

It should be possible to observe a continuous, full-throttle acceleration in 5th gear, from approximately 1600 RPM to around 3600 RPM.

Could any of the esteemed gentlemen here take a look at my Touran and give me some advice on what might be wrong with it?

Seit neuestem (etwa 2 Wochen) habe ich im Stand bei getretener Kupplung außerdem ein "klapperndes" Geräusch vom Motor her, sobald ich (Getriebe im Leerlauf) die Kupplung kommen lassen verschwindet das Geräusch. Hängt das evtl. damit zusammen bzw. was könnte das sein? ZMS?

Thank you very much and best regards,
Markus Seifert.

Hello,

"It's likely that the AGR valve and/or the throttle control are worn out, or there's a problem with the wiring harness to the mass airflow sensor (MAF) or the two components mentioned. You can relatively easily remove the unit and then simply take the covers off. If the plastic teeth are broken -> it's time to throw it away."

"Despite the 'no error' log in the ZIP file, the LMM is still showing significantly low values. It's possible that the wrong part was installed, or a defective part (possibly from China). However, there could also be a problem with the wiring harness, as mentioned above."

Best regards, Rainer.

dieselschrauber wrote:

Even with the "no error log" in the Zip file, the LMM still shows much too low values. It's possible that the wrong part or a defective part (from China) was installed. However, a problem with the wiring harness, as mentioned above, is also conceivable. Best regards, Rainer

Thank you for the information. When the engine light comes on, I clear the error. A little later (usually after about 2 engine starts, which is about 10 km), the error reappears in the engine control unit and can be read, but it's only much later (2-3 days or even weeks) that the light comes on again.

How can I identify / where can I find an inexpensive, good-quality mass airflow sensor (MAF)? I'm ruling out the possibility that it's the wrong part, as the numbers on the old one, the new one, and the eBay listing all matched. The wiring harness looks good, with the original protective tape still in place and undamaged.

Regarding the remaining parts (AGR/throttle valve), I'll see when (and where) I have time to do the work.

Best regards,
Markus.

Certainly not at ****...

What is the question, "Where can I get an LMM?" and "Where did you get your car from?"

dieselschrauber wrote:

What is the question about where to get an LMM, and where did you get your car from?

Well, I bought it used from a private seller after doing some online research. So, did I do everything right by buying the LMM?

Okay, enough with the jokes. The VAG dealerships in this area (and there are quite a few of them) have all disappointed me greatly, which is why I have little trust in them and why I'm trying to learn more about the subject so I don't get ripped off again.

Thank you again for reviewing the logs.

Best regards,
Markus Seifert.

You can still find working replacement parts for the right vehicle there. Alternatively, there are also various online original parts retailers, such as http://www.online-teile.com/.

In your case, I still recommend going to a reputable dealer who can help you find the correct replacement part.

Best regards, Rainer.

Hello!

For the sake of completeness, here's the ending of the story:

So:

After it was confirmed that the sealing plugs were in place, I was passed on to the "problem solver" at the car dealership. He discovered that the PD (common rail) injectors were heavily carbonized, and cleaning wouldn't be effective; a replacement was necessary. This is likely not the cause of the MAF (mass airflow) sensor error, but it is the cause of the power loss.

Since the investment of approximately 2500 euros for 4 PD units without fixing the underlying problem would have been too expensive/unprofitable, I sold the car "as is" to someone named "Ali" and bought a new, used Touran instead.

So: Instead of finding a solution, the problem is simply being disposed of through "exports outside of Europe."

Thank you very much, and best regards.
Markus.

Quote:

He found out

He claims it. I say: extremely unlikely.

The "solution" was therefore to make the car "uninteresting," okay, that's one way to do it...

Nevertheless, thank you for the feedback.

dieselschrauber wrote:

So, the "solution" was to make the car "uninteresting," okay, that's one way to do it...

He didn't benefit from it, as the old car went to a dealer who buys everything, even if it's broken, for export, and the new used car wasn't from that dealership either.

dieselschrauber wrote:

Nevertheless, thank you for the feedback.

You're welcome, thank you for the help!

Best regards,
Markus.

I recently encountered another case where someone insisted on installing their cheap mass airflow sensor from [Brand Name].
After a test drive, the owner returned, and I was allowed to disassemble everything again because the vehicle had lost power at 140 km/h.
Best regards,