Golf 7 2,0TDI Aussetzer im Teillastbereich | Posts 16+

Hello Frank,

Quote:

Does it actually matter if I feel the jolt when I place a marker?

At least then you'll be able to quickly find the relevant entry in the log.

Regarding your problem: My suspicion is that the fuel pressure is dropping because the air mass is decreasing, which in turn reduces the torque output. This means that the required amount of fuel injection decreases, and consequently, the fuel pressure doesn't need to be as high.

It's a bit unfortunate that the target values (fuel pressure and air mass) aren't included, as the sequence of failures would make the cause clearer.

Aber auch so sehe ich dem Luftmassenmesser und seine Verkabelung als heissen Kandidaten. Speak...

I would like to let the engine idle and record only the actual mass airflow value during that process.
Then, wiggle everything around the wiring harness and the mass airflow sensor (MAF). If there's a loose connection, you should be able to see dips in the log data.
Trace the entire cable harness to the engine control unit, which should be located in the water reservoir under the windshield. Also, check for any possible areas of chafing, especially where the cables run over metal edges. Examine carefully, as weasel teeth can leave barely visible marks on the cables while still damaging the copper wire inside.

Best regards, Rainer.

Hello Frank,

The performance drop is clearly visible. It's likely related to the mass airflow sensor or part number G 247.

As described by Rainer, compare the mass flow rate (LMM) with the setpoint and actual values.

After that, I would continue working on the G247 fuel pressure sensor.

Check fuel pressure.

Starting pressure: >150 bar.

Idle pressure: 250-300 bar.

Check the resistance of the wiring from connector G247 to the engine control unit. (And check for loose connections or a broken wire in the wiring).

Pin 2 connects to B55 on the engine control unit (ECU).
Pin 3 connects to B54 from the engine control unit (ECU). - Signal line.
Pin 1 connects to B56 on the engine control unit (ECU). - Ground.

Voltage measurement between pin 1 and pin 3 (connector G 247).

1) Engine off / Ignition on / Connector disconnected = 5 volts.

2) With the connector plugged in while idling = 0.3 - 4.6 volts.

Then repeat the measurement, connecting the vehicle mass to pin 3.
(The measurement results should be the same.)

Then remove the G247 component, visually inspect it, and replace it if necessary.
You might be able to see something when it's unfolded, like a burr or similar imperfection. (This indicates a defective production tool.)

When disassembling, be sure to pay attention to cleanliness . No dirt should get into the system.

Wait until the pressure has subsided . Minimum dwell time: 5 minutes.

verschandeln everything around the valve and then use a wrench or socket with a size of 27 mm to work on it.

When installing, lubricate the threaded portion with diesel fuel.

After assembly MANDATORY, bleed the fuel system using VCDS BLEED .

The TPI (Total Product Index) and the sum of the damage incidents mentioned in the field report related to the G247 lead me to believe that this is likely the case.




Best regards,

Michael.

Hi there,
Could you please provide the CSV files that correspond to those beautiful images?
It seems that at least the uppermost digit is truncated in the pressure readings.
hg
Herbert.

Hello everyone,

"Hey Rainer, I'll check everything next week when I have some time. I think the engine control unit is located near the battery, on the front left side."
The weasel was definitely there before; I had to replace a small vacuum hose last week, but unfortunately, it wasn't the problem.
In the log I uploaded on March 27th, both the actual and target air mass values were recorded. Why is the target value ("SOLL") specified in milligrams (mg)? If that's the case, I should be able to directly log the correct "IST" (actual) and "SOLL" (target) values in the standard log format.

"Michael, your information is from a direct source, thank you for that. Should I check the fuel pressure using a logging tool and then convert it to bar?"
I'll try to measure it. Are the contacts labeled on the engine control unit?
Is the control unit located near the battery in the front? Can I easily access the contacts there?
Can you tell me the part number for the sensor? At our Volkswagen dealer, you can only order parts by part number right now; otherwise, you won't get anything. I think I'll just replace it myself; it shouldn't cost too much.

@ Herbert, I've added the logs.

Thank you all, I think we've found the error soon.
Best regards, Frank.

Hello Frank,

If a friendly raccoon has bitten you, it is definitely worth taking another close look at the area to ensure everything is okay.


You can see the fuel pressure directly in the diagnostic trouble codes (DTCs) or extended measurement values.

The engine control unit is located on the front left side, next to the battery.
The connector is labeled on the inside with markings for the pins.

Do not come into contact with the motor control unit housing while there is a live wire present.

The current part number is 04L 906 054 E, approximately €60.

Please do not lose sight of the software update regarding this error description. Have your dealer quickly check the software version, or read it yourself. (Extended ID)

The following software versions are affected:

6455
6456
6457

If it's the software, we will be writing here for another four months .

Have you ever reset the learning parameters?


Best regards and good luck.

Michael.

Hello Michael,
I will check that as soon as I have some time.
Attached is a log file showing the extended ID from the control unit, but I don't understand anything about the software version.
What learning values are you referring to? I've never adjusted any settings related to "learning values" in this car before.

Thank you. Best regards.

Quote:

04L 906 021 AD Component and/or version: R4 2.0L EDC H22 8135

Your engine control unit has the VAG part number 04L 906 021 AD and software version 8135.

Explanation of VAG part number and software version

Best regards, Rainer.

Hello Frank,

Rainer was very generous. In principle, you are not prohibited from independently exploring the possibilities of this forum.

To the best of my knowledge, it doesn't appear to be related to the software version.

Otherwise, your engine control unit appears to be in its original condition and has not been "optimized."

Therefore, my question about the educational value became irrelevant.
And please don't mess around with it.

According to the system, I am also unable to view any open field operations.

Now it's your turn .

Check the wiring harness.

Air mass setpoint vs. actual value comparison.

Check fuel pressure.


Best regards and good luck.

Michael.

Hi there,
The first error entry

Quote:

: Address 02: Transmission (J743) Label file: DRV\0D9-927-770.clb Part number SW: 0D9 300 041 N, HW: 02E 927 770 AQ. Part number: DQ250-6F MQB H53 4504. Revision: 03253104 Serial Number: TFK01409150204 Coding: 0014 Operating number: WSC 00028 028 00066 ASAM Dataset: EV_TCMDQ250021 001001 ROD: EV_TCMDQ250021.rod VCID: 23121F5A5B5C88A36F0-8076 Two error codes found: 10657 - Engine speed signal from the engine control unit. P0726 00 [002] - Implausible signal. Occasionally - unconfirmed - checked since last deletion. 10763 - Starter motor activation via the selector lever sensor. P1734 00 [002] - - Occasionally - unconfirmed - checked since the last deletion

still holds another possibility. Please, during the next test drive, if there is an error, read out the fault memory of the engine and transmission before stopping the engine.
It's not that the DSG (direct-shift gearbox) is malfunctioning – it wants to shift, but can't – and therefore the engine torque is being reduced. There are a few forum threads about this online.
hg
Herbert.

Hello everyone,

Even three months later, the problems unfortunately haven't gone away; in fact, they seem to be getting worse.
I visited two Volkswagen workshops in the meantime, and neither of them found any broken wires or other issues. Unfortunately, two independent garages also couldn't find anything.
I'm stuck and considering trading in the vehicle; it seems I can't make any further progress. Two weeks ago, I had the DSG oil changed as required at 120,000 km, because I thought the problem might be with the DSG transmission.

I'm having trouble with all these Log readings; I don't have much experience identifying errors. Last week, in addition to the usual jolts when stopped, the following occurred: While in "D" mode, the brakes were applied at a traffic light.
Suddenly, the engine cut out. There were no error messages, nothing on the display. I turned off the ignition and restarted the engine, and it ran normally. This happened for the second time this week. I checked all the wiring earlier, but I couldn't find any faults. Then, as a test, I disconnected the mass airflow sensor (MAF). The glow plug indicator blinked, which is logical. The car drove normally, although it still felt like it was misfiring. Therefore, I'm ruling out the MAF sensor for now.My girlfriend, who mainly drives the car, also thinks that when it stutters, it brakes as well – not normal engine braking, but a strong braking force during the jerks. I'm at a loss for what to do next; do you have any more suggestions?

Thank you very much. Best regards, Frank.

Hello, here is an API from Volkswagen.

Tachometer/Speed sensor is not required.

DQ250
Information:
The mechatronic unit for the DQ250 gearbox (MQB platform) is no longer compatible with...
Equipped with an input speed sensor. The transmission control unit uses this...
Signal from the engine control unit (ECU).
The signal is transmitted via a separate power connection between the motor control unit (MCU) and...
introduced to the transmission group.

Possible errors:
The error code P072600 – speed signal – is only recorded in the transmission control module (TCM) memory.
"Implausible signal from the engine control unit."
There may also be malfunctions in the transmission function (e.g., jerking). There may also be malfunctions in the transmission function (e.g., jerking).

Solution/Workshop/Action/Repair:
Check the power cable connection between the motor control unit (MCU) and the transmission control unit (TCU) (pin not connected).
(Locked/engaged, but the retaining clip on the transmission gear selector is not locked).

(If no error can be found, try replacing the cable as a test.)

Best regards,
Dago

Hi everyone, luckily I have a second vehicle with the same engine/transmission, and I was able to check it out. The car drives great, but it also has that speed signal error in the transmission.

I was able to create another log today.
What I've noticed is that the tachometer now drops to zero along with the engine speed during the misfires.
Attached is a log file.

Thank you very much.

Hello,

Is there a glitch or error in the log, and if so, where?

Best regards, Rainer.

Hello, at the 46-second mark, a marker was placed shortly after.

Best regards,

Hello,

Based on the data, I don't see any interruptions in the measured values or changes to the sampling grid of the measurements around the 46-second mark. Therefore, I would rule out problems with the power supply from the engine control unit.

Despite a slight increase in the accelerator pedal position, the target value for rail pressure decreases. This means that if you haven't been driving on an undulating road, the engine control unit likely intentionally reduced the injection quantity. Lower injection quantities are typically used with lower rail pressures.

Most likely, the problem is caused by faulty sensor signals. For example, this could be related to the mass airflow sensor (MAF), brake pedal position/brake pressure, or any of the various temperature sensors (coolant, exhaust gas temperature, charge air temperature). You should check these one by one if you experience jerking. It's also essential to inspect the wiring and connectors, as well as any areas where the cable harness for the engine control unit or the sensors might be chafed.

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.

Hello,

Here's a log of the turbocharger boost pressure; I'll be creating more logs using different sensors.
It definitely has to be a sensor that can shut off the engine while idling without storing any error codes. How does start-stop work? Does it come from the engine control unit (ECU)? Which signal does it cut off?

Best regards, Frank.