Golf 7 2.0 TDI - Hesitation/Misfire at Partial Load

Hello everyone, I've been having a problem with my Golf 7 (2.0 TDI CRLB engine) for quite some time now – it keeps stalling intermittently. It feels like the accelerator is suddenly released and then pressed again. The error memory is clear, and I've attached an auto-log. Where should I start looking for the cause of this issue? This problem doesn't occur very often, but yesterday it even happened while idling that the engine stalled completely, although it started up without any problems afterwards. Thank you very much for your help.

Frank1986 wrote:

Hallo Leute, ich habe seid geraumer Zeit an meinem Golf 7 mit 2,0 TDI CRLB Motor das Problem das er richtige Aussetzer hat, fühlt sich so an als würde man plötzlich vom Gaspedal gehen und wieder drauf, Fehlerspeicher ist leer, im Anhang ein Auto-Log, wo könnte man da Ansetzen für die Fehlerdiagnose? Repruduziertbar ist das ganze eher weniger, gestern kam es im Leerlauf sogar vor das der Motor Ausging, sich aber ohne Probleme wieder Starten ließ. Vi"Thank you for your help."

Hi Frank,

I would simply start logging the operating voltage from the engine control unit to a file and then drive until you notice any interruptions or malfunctions.
If there are voltage drops recorded in the log file or gaps in the timestamps, it indicates either interruptions in the power supply from the engine control unit or resets caused by other reasons.

Best regards, Rainer.

Hi Rainer, does the Extended Motor Control Board (MWB) have an option for the operating voltage of the control unit? For some reason, the issue never occurs at full load, but only at partial load. Best regards.

Frank1986 wrote:

Hallo Rainer, gibt es in den Erweiterten MWB eine Option für die Betriebsspannung des Steuergerätes? Komischerweise kommt der Aussetzer nie im Vollastbereich vor nur bei Teillast. Ggreetings

Yes, you can type search text into the input field above the list in the advanced measurement blocks.

Hi there.

"It probably has nothing to do with it, but on Sunday I had the exact same symptoms in my Passat Variant 2.5 TDI 4-Motion with a BDH engine: no error codes were stored, but I heard a slight noise from the timing belt system. The main timing belt had slipped and was so severely damaged that it was about to break. Luckily, I caught it in time."

Hi everyone, I'm having a major problem with my Golf 7 2.0 TDI with a 6-speed DSG transmission, manufactured in 2015 and with approximately 113,000 km on the clock. For several months now, it's been experiencing intermittent issues while driving and accelerating; it feels like something is braking.
Heute bin ich 100Km gefahren ohne Probleme. 4 Stunden Später wollte ich Heim fahren. Also ab auf die Autobahn und schon fing das Drama an, sehr Starke Aussetzer beim Beschleunigen mehrmals Hintereinander, konnte das Gaspedal durchdrücken wie ich wollte nichts ging. Hatte echt Angst liegenzubleiben mit 2 Kleinen Kindern auf der Autobahn :thumbdown: . So schlimm war es noch nie. Hab dann mal getestet wie sich das ungefähr anfühlt, das is wie wenn man mit 100km/h vor sich hin fährt und während dem Gas geben die Bremse leicht drückt, ohne zu Bremsen nur so das das Auto merkt man Bremst, er nimmt das Gas weg und es geht ein Ruck durch das ganze Auto und man kann Gas geben wie man will. Das ging 4-5x mal hin und her. Dann war es nicht mehr. Im "Tacho" has nothing."The check engine light is either on or was recently on, but there are no error codes stored. The timing belt is currently running. The diesel filter is old (4000 km). The engine control unit also shows no voltage fluctuations. I'm at a loss."

Good evening, Frank.

The Volkswagen Golf Mk7 models have issues with the wiring harness in the area of the intercooler.

Typical symptoms: engine misfires or starts poorly & no error codes in the engine control unit.

An additional cable clip needs to be installed here to prevent further damage to the wiring harness.


I would appreciate any feedback you can provide, even if the wiring harness is fine.


In addition, there is a recall campaign for the Golf 7 (model year 2015) due to defective engine control units. Have your dealer check the Vehicle Identification Number (VIN) to see if your car is affected.

Best regards,

Michael.

Hi Michael, do you have a reference number or anything like that for the recall campaign? Our Volkswagen dealer tends to be quite difficult about these things. Thanks, best regards.

Hi Michael, I checked earlier, and it should be located to the right of the EGR cooler, where you mentioned about the cable.
Everything looks good.

Good evening, Frank.

Thank you for your feedback.

The wiring harness looks good at first glance.

Have you ever moved the wiring harness while the engine was running?

The action for the engine control unit is designated as 23O2. You need to have your dealer check whether your vehicle is affected by this issue.


Rainer and Rüdi have also given you very valuable tips, which you apparently can also exclude as potential sources of error.


Please log another trip using the KDataScope until the errors occur. Perhaps you'll find an anomaly that isn't relevant to a specific error entry.

Pay particular attention to the fuel pressure (G247).


"Edit: There should be a sticker located in the spare tire well. Measure number 2302. If there is no sticker, take it to the dealer."





Best regards,

Michael.

Hi Michael, regarding the sticker, I need to take a look; I just know there was a recall campaign related to the oxygen sensor. Yesterday, I had a chance to record some data while driving and set two markers where the jerking occurred. Unfortunately, I can't see anything obvious in the data myself. I haven't moved any of the wiring harnesses yet while the engine is running. The log file includes an older version as well; I don't know why that is, but the one I have is from yesterday, March 26, 2021.

Hello Frank,

I just briefly checked where markers 1 and 2 are located.
Generally, less data is sometimes more, as it increases the temporal resolution of the log file. Whenever possible, use turbo/grouping to increase the temporal resolution (sampling rate). It also doesn't make sense to log the same measurement in different units (e.g., mass flow rate in g/s and mg/stroke).

Regarding proper logging:
Ich kann den Inhalt dieser URL nicht abrufen und übersetzen. Bitte gib mir den Text, den du übersetzt haben möchtest.

What I've noticed is that the air mass seems to be decreasing at the marker locations. However, it's difficult to interpret this accurately due to the poor temporal resolution and constant fluctuations.

I agree with Ich_Can_nix's suggestion about potential wiring harness problems. Generally speaking, if the torque limited by the air mass becomes lower than the torque limited by the transmission, you will feel a drop in torque while driving.

There's a lot to read about this; search for "torque limiting" and also check out the similar posts listed at the bottom of each article.

I would like to let the engine idle and record only the fuel pressure and actual air mass readings.
Then wiggle everything around the wiring harness, the mass airflow sensor (MAF), the fuel pressure sensor, etc. If there's a loose connection, you should see dips in the log data; otherwise, the idle speed will likely keep things relatively constant.

Best regards, Rainer.

Hello Frank,

If you've followed Reiner's tips and are still unable to make progress, a test drive with another person can be very helpful. Carefully examine and compare the parameters. Try to minimize errors by maintaining as consistent driving behavior as possible. This will reduce the number of values that need to be compared.

Just before the set point, it looks like the fuel pressure might be dropping slightly. What was the position of the gas pedal?

If you are looking for deviations in the fuel/air system, please record the throttle pedal position.

What I've noticed is that your problem occurs below 3000 RPM. You could try disconnecting the fuel pressure sensor connector and driving without it!

The engine control unit then uses a substitute value and limits the engine speed to 3000 RPM (limp-home mode).

If the error is no longer occurring, then it's either the sensor or something on the fuel side.

If the error still occurs, we need to continue searching , but at least we have ruled out one suspect.

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

"After that, delete any errors."


Okay, I understand. Please provide the German text you want me to translate into English. I will then give you only the translation and follow up with a brief feedback on my progress and what still needs to be done.

Do you still have no error entries, not even any occasional ones?


Best regards,

Michael.

Hello Frank,

I have another piece of information!

There were problems in production due to a faulty tool used in the manufacturing of rail pressure sensors.

For more information, please refer to document TPI 2048484/7.

Faulty rail pressure sensor - engine occasionally fails to start or misfires; no error codes registered in the engine control unit.

Why is there no error entry? The field report indicates worn-out springs in the sensor. This means the sensor is providing inaccurate readings without anyone realizing it.

You should take a close look at the component and check it carefully. (See previous post).

That doesn't mean your car has this problem, but it is a possibility.

You can now simply replace the sensor for €60 - maybe you'll get lucky - but if not, you shouldn't complain to us. You are welcome to thank us .

Please also review and do not neglect all the other tips that you, especially from Rainer, have received. They cost nothing, but are still very valuable .

Best regards,

Michael.

Hello Rainer and Michael,

I'm going to add my statement to everything.
I went back to the car a little while ago to finally get that problem sorted out.

"I checked the fuel pressure and mass airflow sensor readings earlier, and I wiggled all the cables and connectors at the front of the engine bay, but didn't find anything loose. There's also nothing unusual in the log data; everything seems consistent with no noticeable drops or fluctuations."

After that, I unplugged the sensor and continued driving.
der ist ja im Notlauf sowas von langsam unglaublich . Ich hatte 1x das Gefühl dass er geruckt hatte, konnte das aber nicht richtig fühlen, da er gleichzeitig hoch geschaltet hat, ich bin mir da unsicher.... werde das daher nochmal wiederholen um sicher zu sein. Dann hab ich den Stecker wieder drauf und den Fehler gelöscht, und nochmals Gaspedal/Luftmasse und Kraftstoffdruck aufgezeichnet, natürlich trat der Fehler nicht mehr auf . Was mir bisher aufgefallen ist, der Fehler tritt eher auf wenn man langsamer Beschleunigt, und es eher wärmer ist. NeUnfortunately, there are no errors, not even occasional ones.
To be honest, I'm still having some problems with the logs. I can record them, but when I try to view them, I get lost. For example, I can't seem to see the markers that I add to the log. Also, I don't know how to view multiple curves at once; it always shows me two curves. Well, I haven't really delved into this before, but I'm sure I'll figure it out eventually. Is it actually useful to set a marker whenever I feel a jolt?
Finally, I would like to express my sincere gratitude to all of you, and I am very happy that I bought VCDS from Rainer, mainly because of the help available here in the forum.

Best regards, Frank.

Hallo Leute, heut war es endlich mal soweit das ich an meinem Problem weiter komme, konnte mich selber an den Laptop setzen als Beifahrer. Ich habe dann mal 2 Logs gemacht mit der Markierung, mich ein wenig mit KDataScope eingearbeitet. Hab jetzt mal 4 Bilder von den Daten gemacht und im Anhang eingefügt. Auffällig ist, dass Luftmasse und Kraftstoffdruck abfallen, obwohl Gaspedal gleich. HIt would be helpful for further troubleshooting if I could have access to the logs. One of them is 900 seconds long, and my computer is reacting very slowly to it.

Thank you very much. Best regards, Frank.