Notlauf Fehlercode 0519 --> geht wieder - aber warum | Posts 16+

toni66 wrote:

wo finde ich eig den G71 beim AKE? Sincerely.

Undercarriage protection removed. It's located in the intercooler on the aKE.4 models. It has a 4-pin sensor. If it's an original part, it will say "Bosch" on it.

hello,

Yesterday evening, I removed the undercarriage protection to access the sensor. On a 2001 AKE model, the sensor is located on top of the transmission. To reach it, simply remove the left headlight. It was slightly oily, so I cleaned it up a bit. The resistance between pin 1 and pin 2 is 1.8 kOhms (with a cold engine). The sensor has 4 pins, but the connector only has 3 connections. Why is that? With the ignition on, there's 4.8V present at "pin" 3 and "pin" 4 of the connector.I then reassembled everything. I cleared the error memory. I briefly started the engine -> no errors in the error memory. Afterwards, I took it for a test drive and the turbo was working again .

It actually looks nice, but I don't know what I did or what caused it. It bothers me a little bit. I took a picture of the G31. Does it look normal like that? (So "round" at the sensor).

<<Photos>>

"And what is the difference between G71 (as shown in the fault memory) and G31 (according to the Audi exploded diagram)?"

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

"lg" translates to "best regards" or "kindly regards" in English. It is a common abbreviation used at the end of emails and letters.

Please also consider the wiring and connectors for the turbocharger pressure sensor... A loose connection can lead to potentially inaccurate turbocharger pressure readings.

Best regards, Rainer.

Hello Rainer, Steffen, and everyone else,

How oily is the pump usually? Because cleaning it is the only thing I've done so far.
I still have two questions.
Why does the connector have 4 pins, but only 3 of them are connected?
Where does the difference in designation between G31 and G71 originate?

After the intermittent connection issue, I will investigate further when the problem occurs again. For now, however, I will follow the saying: [followed by the proverb].

"Don't touch a running system." suffice

Let's see how long it lasts. Thanks -> Best regards.

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How oily is the donor usually?

Oily...

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Because cleaning would have been the only thing I did "

".
Hopefully, it wasn't filled with compressed air at 10 bar.

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1. Why does the sender have 4 pins, but only 3 are connected on the connector?

I have no idea. The sensor measures two things: boost pressure and temperature. It requires at least 4 pins to do this.

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2. Where does the difference in designation between G31 and G71 come from?

Temperature and pressure?
G31 = Sensor for boost pressure.
G71 = Intake manifold pressure sensor with air intake temperature sensor.

Your picture shows a G71. If only 3 wires are connected, I wonder how the intake air temperature is then determined. Take a look at where the G42 should be according to your diagram.

Best regards, Rainer.

I'll check where the G42 sensor is located... according to VAG-COM, it should have a value, so I'm sure I'll be able to find it (hopefully).

Another 0519 update:
"Der schnelle braune Fuchs springt über den faulen Hund."
... it seems like the G71 (G31) sensor is faulty. The car ran for about 100 km without any problems, then the same symptoms reappeared -> error code 0519: implausible signal. I cleaned the G71 sensor again as I did yesterday, and now it's working again... so I guess I will replace it after all.

@steffen: The number is 038 906 051 B . If you have another one, we might be able to come to the store. I have to go to LE tomorrow and will definitely be driving via ABG... maybe you'll see this.

Best regards }.

I've read it; I'll tell you about it tonight.
I apologize for the underbody protection. I assumed it was an A6, but it's actually an A4.
"The three cables must also be the correct type. Wire number 4 connects to pin 36 of the MSG and is only active from production date MJ 03 onwards."

I only have one left, and it ends with the number 177. It won't work for you.
I also believe that your car doesn't have a combination sensor either. It only measures the boost pressure in that model. I vaguely remember that a similar Audi had the same problem once. In that case, it turned out to be the mass airflow sensor. The temperature sensor (G71) was integrated into it. And that particular part wasn't available as an inexpensive Bosch replacement; it was only from Hella and was expensive. However, I'm not entirely sure anymore because it happened a while ago. This needs to be clarified because if you have the same issue, you're replacing your G31 sensor unnecessarily.

hello steffen,

"Thanks for looking into this. My colleague also says that the mass airflow sensor (MAF) provides temperature data. What's a bit confusing is that the G42 sensor seems to display real values in VAG-COM. But who knows how the MSG [Motor Steuergerät - Engine Control Unit] is programmed. Can you give me a tip on where I can learn more about evaluating measurement blocks (MB)? "

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

"LG" translates to "Best regards" or "Sincerely" in English. It is a common abbreviation used at the end of emails and letters.

Hi,

Quote:

I also think that you don't have a combined provider either.

The black pearl in his image is the temperature sensor. However, since one of the pins is not connected, it probably won't be evaluated.

Best regards, Rainer.

That's more than obvious. This sensor is used in various other models, including 3-cylinder and 4-cylinder TDIs. In those cases, all four pins are connected, and it's used as a dual sensor.

hello,

"It's probably going to be like that. I'll try disconnecting the connector from the mass airflow sensor (MAF). Then, hopefully, no temperature value will be displayed in VAG-COM for sensor G42 (at least then I'll know if the MAF is still transmitting the temperature reading?)."

By the way, regarding my problem, the latest status: I replaced the boost pressure sensor, and since then it's been running... hopefully, that will continue... (I've already read with horror online about the money-pit AKE).

Wishing you a lovely weekend!

Hello,

Quote:

then no temperature values should be displayed in VAG-COM anymore

.
It will then either use a fixed replacement value or the temperature reading from another sensor with a similar temperature (depending on which sensor it is and what the specific application developer intended).

Best regards, Rainer.