1.9 TDI AWX: Idle Jerking/Stalling - Causes & Fixes

I'm editing the post because new developments have occurred in the meantime.

Hello,

"This refers to the following vehicle:"
- Skoda Superb 3U4 1.9 TDI AWX, 06/05, 131 hp, ~475,000 km, approximately 300,000 km ago, performance optimization via MSG adjustment, AGR valve "disabled" using a plate during the process.

Auto-scan VCDS:
Sunday, August 3, 2025, 10:04:04:48728.
VCDS, a Windows-based VAG/VAS emulator, now runs on Windows 11 x64.
VCDS Version: DRV 24.7.1.0
Data as of: 20241105 DS356.3
shop.dieselschrauber.org

Dealer/Workshop name: Daniel.

Vehicle Identification Number (VIN): TMBBU63UX5xxxxxxx
License plate:
Mileage: 473,150 km. Repair order:



"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."


Vehicle type: 3U (3U - Skoda Superb I (2002 > 2008))
Scan: 01 02 03 08 15 16 17 19 36 37 46 47 55 56 76

Vehicle Identification Number: TMBBU63UX5xxxxxxx
Mileage: 473,150 km
"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 01: Engine Control Module
Label file: DRV\038-906-019-AVF.lbl
Part number: 038 906 019 KE.
Part: 1.9L R4 EDC G000SG 4898
Coding: 00005
Operating number: WSC 36345.
VCID: 64C0141FF4E5E7B64F-4B1A
TMBBU63UX59089948 SKZ7Z0D2790065

"One error found:"
18263 - Data bus driver.
P1855 - 35-10 - Software Status Monitoring - Intermittent.
Readiness: 0 0 0 0 1 0

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 03: Brake Electronics
Label file: DRV\3U0-614-517.lbl
Part number: 3U0 614 517 D
Component: ABS/ESP front 1314
Coding: 04255
Operating number: WSC 00028
VCID: 3460A45F048537361F-5122

No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 08: Climate Control/Heating. Label file: DRV\3U0-907-044.lbl
Part number: 3U0 907 044 A
Part: CLIMATRONIC S B5 C 2004
Encoding: 17000
Operating number: WSC 00028
VCID: 316EAD4BFB97021E74-515E

"One error found:"
01271 - Temperature flap actuator (V68)
37-00 - defective.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 15: Airbag
Label file: DRV\6Q0-909-605-VW5.lbl
Part number: 1C0 909 605 F
Part: 0D AIRBAG VW61 0K 0003
Encoding: 12356
Operating number: WSC 00028
VCID: 275A4313C5534CAEAA-5122

No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 16: Steering wheel electronics
Label file: DRV\1J0-907-487-A.lbl
Part number: 1J0 907 487 A
Component: Steering wheel electronics 0005.
Encoding: 00118
Operating number: WSC 00028
VCID: 2F6AAB33EDA314EE62-515E

"One error found:"
01336 - Corporate Data Bus Comfort.
80-00 - in single-wire operation.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 17: Control panel module
Label file: DRV\3U0-920-xxx-17.lbl
Part number: 3U0 920 841 A
Component: COMBINATION INSTRUMENT + SPEEDOMETER VDO V06
Encoding: 23105
Operating number: WSC 00000
VCID: 316EAD4BFB97021E74-5122
TMBBU63UX59089948 SKZ7Z0D2790065

2 error codes found:
01336 - Corporate Data Bus Comfort.
49-10 - No communication - Intermittent.
00476 - Control unit for fuel pump (J538)
49-00 - No communication.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 19: Diagnostic interface
Label file: DRV\6N0-909-901-19.clb
Part number: 6N0 909 901.
Component: Gateway K<->CAN 0001
Encoding: 00006
Operating number: WSC 00028
VCID: 70E8684F301D4B163B-5122

4 error codes found:
01336 - Corporate Data Bus Comfort.
49-10 - No communication - Intermittent.
00476 - Control unit for fuel pump (J538)
49-00 - No communication.
00463 - Control unit for the Digital Sound Package (J525).
49-00 - No communication.
01303 - Transmitting and receiving device for telephone (R36).
49-00 - No communication.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 36: Seat adjustment for driver.
Label file: DRV\3B1-959-760.lbl
Part number: 3B1 959 760 E.
Component: °301
Operating number: WSC 00000 065 00000
VCID: 2F6AAB33BDA314EE62-5122

No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 37: Navigation
Label file: DRV\3B0-919-887.lbl
Part number: 1U0 919 887 BX
Component: Navigation BNO 0102
Encoding: 00002
Operating number: WSC 00000
VCID: 1A3C6AE78621E14625-4B00

"One error found:"
00862 - Antenna for navigation (GPS) (R50)/(R52)
44-10 - Short circuit - Intermittent.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 46: Comfort System
Label file: DRV\1C0-959-799.lbl
Part number: 1C0 959 799 B.
Component: BD Comfort Device HLO 0004.
Encoding: 00259
Operating number: WSC 00028
VCID: 36649E5712F9252621-4B1A

Subsystem 1 - Part number: 1C0959801.
Component: BD Throttle Control.FS KLO 0202

Subsystem 2 - Part number: 1C0959802A
Component: BD Throttle Control.BF KLO 0202

Subsystem 3 - Part number: 3U0959811.
Component: BD Throttle Control.HL KLO 0202

Subsystem 4 - Part number: 3U0959812.
Component: BD Throttle Control.HR KLO 0202

3 error codes found:
01336 - Corporate Data Bus Comfort.
80-00 - in single-wire operation.
01336 - Corporate Data Bus Comfort.
37-10 - defective - intermittent.
00930 - Rear left central locking control unit (F222)
27-10 - implausible signal - sporadic.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 47: Soundsystem
Label file: DRV\1J0-035-456.lbl
Part number: 3U0 035 456 B
Component: Sound processor 3.
Coding: 00571
Operating number: WSC 00028
VCID: 316EAD4BFB97021E74-4AE8

No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 56: Radio
Label file: DRV\3B0-035-186.lbl
Part number: 3B0 035 186 DX
Component: Radio BNO 0102
Encoding: 00400
Operating number: WSC 56405
VCID: 78F8506F586D1356F3-4AE8

2 error codes found:
00852 - Front speakers.
36-00 - Interruption.
00853 - Rear speakers.
36-00 - Interruption.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein."
Address 76: Parking Assist
Label file: DRV\3U0-919-283-7X1.lbl
Part number: 3U0 919 283.
Component: Parking Assist System V009
Encoding: 00114
Operating number: WSC 00028
VCID: 78F8506F586D1356F3-4BB0

No error codes found.

End----------------------------(Duration: 02:51)-----------------------------

"Recently, I've been experiencing the following problem with my car: A few weeks ago, I occasionally (sometimes twice during a commute to work, which is about 40km each way) experienced a brief, hard jolt. The idle was normal, there was full power, no excessive soot when accelerating, and no increased fuel consumption. We then replaced the diesel filter and the gasket for the valve on the filter (manufacturer UFI). After that, things were quiet for a few days, and we thought we had found the problem."



"Now, it seems that the engine almost regularly, but not constantly, experiences a misfire at idle, which causes the engine speed to drop briefly by about 100 RPM. Once, it even stalled in the morning, but it started without any problems. Yesterday, it also stalled when I was disengaging the clutch to approach a traffic light. However, it started immediately again, and I was able to continue driving normally. The engine performance is as expected, and it accelerates properly."

"It now idles roughly on a regular basis, but the problem disappears when I accelerate. I suspect a fuel supply issue, specifically with the tandem pump."

Yesterday, we replaced the PD wiring harness (original VW) and the valve on the diesel filter, but there was no improvement.

The colleague from the other forum, based on the video, expressed a rather clear suspicion of a tandem pump issue. I already purchased a replacement from Pierburg a few months ago, and we will be replacing it tonight, hoping to solve the problem.

If that's not the problem, would you know what else could be causing these symptoms?

Thank you in advance for your thoughts and assistance!

Best regards,
Daniel

Okay, so we replaced the tandem pump today, but there's still no improvement.

Two minutes after we swapped them, the engine ran smoothly at idle without any problems, but then the issues started again. It seems like the problem gets worse over time when the engine is idling.

He shouldn't have worked properly, considering we hadn't created a vacuum in the fuel lines and the new tandem pump was initially empty, but it actually did work.

It started immediately after the change, with a brief sputtering sound. It ran perfectly smoothly for 2 minutes, then it started sputtering more and more frequently. We took it for a test drive, and as always, everything was great: full power and excellent throttle response. Then, after 20-30 seconds of idling, it started sputtering again.

I then drove home, which was about 30km on the highway. Everything worked perfectly, with full power, and the cruise control maintained 150km/h without any jerks or issues. The first 2-3 traffic lights were fine, but then, at the parcel locker, it started to stutter while idling. At the next traffic light, it stalled again, but it started up immediately.

The problem still only occurs at idle and occasionally at low RPMs, roughly up to about 1200 RPM. I have the feeling that after it has been given some throttle for a while, it runs smoothly for a short time and then starts to stutter without any throttle input.

If you maintain an idle speed of approximately 1300 RPM or higher, it won't stall.

Help... :S

What has been done so far:

- New diesel filter from UFI -> I think the jerking at idle started after installing this filter. Maybe I should replace it again with a MANN FILTER one that I have in stock?

- new valve on the Bosch diesel filter.

- New, genuine wiring harness from VW.

- New tandem pump from Pierburg.

One hopes that nothing major is wrong with it. I would actually like to keep driving this car for a while, but of course, I need a reliable vehicle.

Ich habe irgendwie das Gefühl das sich im Stand immer wieder Luft im Kraftstoffsystem bildet... Could that be possible?

Thank you again for your help!

Have a good evening!

Hi,

I had asked you to upload the YouTube video to the topic, but unfortunately, it was unsuccessful.

Quote:

It shouldn't have worked properly, because we hadn't created a vacuum in the fuel lines, and the new tandem pump was also initially empty, but that wasn't the case. He started immediately after the switch, ran perfectly smoothly for 2 minutes, and then started to misfire more and more frequently.

What does "Verschlucken" mean?

That's the key point.

If the fuel pressure at the tandem pump is okay when the engine is idling, then the problem is not related to the fuel supply when it "bogs down."

I would, for example, log the power supply voltage and the ECU's speed with the highest possible sampling rate and then check whether the timestamps in the log are equidistant.

If that's not the case, there's a problem with the ECU or its power supply.

Best regards, Rainer.

Hi Rainer, I couldn't find any messages from you, or did I miss something? Sorry about that. X

"Stalling" refers to a brief period of rough running, which is what you might expect if the fuel system was exposed.

I'll record a video of the car running at idle later and upload it to YouTube.

Just to understand, if there is actually a voltage problem, it could potentially be due to a relay located in the engine compartment, directly connected to the engine control unit.

I had already taken a picture of it before, and it has the part number "443 951 253 AA".

Can you briefly outline how I can use VCDS to log the voltage supply, in a way that's useful for you? I've never used the function before.

Thank you very much!

Hello Rainer,

I now let the engine idle, and as expected, it barely sputtered at all; it was cold, of course. I made a video, and you can only hear it briefly, maybe once or twice.

I also logged the engine speed and terminal 30; I hope I did that correctly.

In the Excel file, there's nothing initially visible, and I've been monitoring the voltage the entire time. I didn't observe any drop, even when it seemed to be flickering.

Don't be surprised that I started the recording multiple times; he just rarely exhibited the symptom, and I didn't want a recording that was endlessly long without showing the problem.

As I mentioned, I didn't purchase VCDS through their website, so I don't have a KDataScope.

In the video, you can hear the misfires at 0:35, 0:49, and 1:05. This is still relatively infrequent; once the engine warms up, it will happen more often, and it will stall if you don't give it gas, as mentioned. There are no issues when accelerating or during normal driving.

PS: It seems that the video quality was severely degraded during the upload process; the audio is terrible, and therefore I don't think the video is usable.

Quote:

P.S.: The video seems to have been severely degraded in quality during the upload process; the audio is terrible, and therefore I don't think the video is usable.

Then upload a higher quality version.

I've mentioned YouTube links enough times now; I'm just going to delete them from now on. No one wants topics with dead links.

Uploading a log file where nothing is stuttering is - surprisingly - useless. Please skip the unnecessary Excel conversion.

Hello Rainer, I'm sorry, I don't want to cause any trouble...

I'm uploading the file again in CSV format, and the video is in .MOV format (which should be an allowed file format). It has excellent quality on my computer. I'm not sure what went wrong with the previous upload that caused it to be downscaled.

The video isn't playing in the preview right now, but I hope it works when it's posted.

You can hear the glitches at the beginning, shortly after, and at the end.

While I was creating the log file, I also noticed some interruptions. However, I couldn't observe any voltage drops in the live data. Perhaps the sampling rate wasn't high enough to capture them at that moment?

Best regards,
Daniel

Hello,

I found places in the first two log files where the difference in timestamps had deviations larger than the usual value of ~0.65 seconds.
Unfortunately, the "glitches" are very short. In my opinion, the most likely causes are either the wiring of the pressure sensors or power supply disturbances to the ECU.

Logging the supply voltage value via diagnostics is, in my opinion, not a useful practice, because if the ECU is reset, the value is neither accessible nor current.

My suggestion would be to record only one measurement with the highest possible sampling rate, and if there's a drop-out, press the "MARKER" button in VCDS. This will mark the point in the log.

Quote:

At the parcel locker, he started stuttering again.

While stopped at the next traffic light, the car stalled again. }
Going out is simply not possible with a shaky connection on a Power Distribution (PD) module. Either the power to the Engine Control Unit (ECU) is cut off, or there are massive disturbances in the vehicle's electrical system (I once had a corroded fuse box in an A3 8L that intermittently shut off the engine).

In cases of the described behavior, the most common culprit is the relay responsible for supplying power to the ECU. It's relatively inexpensive, and I would recommend replacing it. While doing so, also check the fuse box and connectors for signs of wear and tear. Additionally, worn wiring harnesses leading to the ECU, particularly those where the cable insulation is rubbed away against metal edges, should be inspected.

Best regards, Rainer.

Hello Rainer, thank you for your reply. I was starting to despair again because the video quality is such a disaster again, even though it's not quite as bad as the first video. I didn't expect a storm to break out over me right away.

Okay, thank you very much for your suggestion. I'll follow your advice and, as the simplest option, purchase and replace the relay that's directly connected to the engine control unit (ECU) from a VW dealer.

As we mentioned, we had already obtained and replaced the PD wiring harness from VW originally.

We will visually inspect the engine wiring harness for any abnormalities.

The control unit is located on the driver's side in my car, and there's a black relay with part number "443 951 253 AA" there. Are we talking about this relay?

Just to clarify my basic understanding, it's possible that the power supply could be causing these issues at idle or very low RPMs, but everything is fine at full load, right?

Thank you so much again, I'll get back to you as soon as I know something new!

Hello.

Quote:

The control unit is located on the driver's side in my car, and there's a black relay with part number "443 951 253 AA" there. Are we talking about this relay specifically?

Possibly, I would check the vehicle's wiring diagram to see if it's the correct relay.

Quote:

Just to clarify my layman's understanding, it's possible that the power supply could cause such problems at idle or very low RPMs, but everything is fine at full load, right?

Defect = Roulette, when it works.

Hello.

Quote:

The control unit is located on the driver's side in my car, and there's a black relay with part number "443 951 253 AA" there. Are we talking about this relay specifically?

Possibly, I would check the vehicle's wiring diagram to see if it's the correct relay.

Quote:

Just to clarify my layman's understanding, it's possible that the power supply could cause such problems at idle or very low RPMs, but everything is fine at full load, right?

Defect = Roulette wheel, when it works .

Hi Rainer, all good. We'll replace the relay, check the wiring harness for any faults, and just to be safe, we'll swap the UFI diesel filter for a Mann filter (which I had in there before).

I hope that one of these two options is correct.

Maybe it's somehow related to the diesel filter (Made in China), because the problems at idle actually started about 2 weeks after the filter was installed. Sometimes things are just strange.

I'll get back to you!

Evening, Rainer,

nochmal ein abendliches Gedankenspiel. Ich habe eigentlich immer ein kurzes "Plätschern" aus Richtung Kofferraum vernommen, wenn ich die Zündung bei meinem Wagen eingeschaltet habe. Das habe ich jetzt schon ewig nicht mehr gehört. Ich habe jetzt gelesen, dass mein Motor zum reinen Fahren und auch volle Leistung haben, zumindest mit relativ vollem Tank alleinig mit der Tandempumpe auskommt. Er benötigt die Vorförderpumpe im Tank lediglich im Leerlauf und wenn der Tank relativ leer ist, weil die Tandempumpe nicht genügend Druck macht um sich Leerlauf mit genügend Sprit zu versorgen. KanIs that it?

Could my problem possibly be related to a faulty pre-lift pump or the corresponding relay?

Edit: Okay, but then it shouldn't start up again immediately afterwards, that seems silly, right?

Best regards and have a pleasant evening.

Daniel.

Good morning, Rainer. I have some news. I just accessed the pre-lift pump via channel 35 in VCDS, and I can hear it.

However, during this test, the car suddenly displayed an error message that said "Engine malfunction, visit workshop."

I'm actually quite glad about the mistake, which is something you usually wouldn't be.

Error code:

"18027 - Relay for glow plugs (J52)"
P1619 - 35-00 - Short circuit/open circuit to ground.
Readiness: 0 0 0 0 1"

Could this be the root of all evil?

Or was this simply because the pump drew so much power that the relay was momentarily underpowered at that moment?

I'm definitely going to call VW right now and try to get the relay today. You have to try everything.

Luckily, it's arriving today. Then I can install it this evening.

That was likely the old relay 109, used in older TDIs and officially designated as the glow plug relay, but also responsible for supplying power to the engine control unit.

For me, it's a blue one with the inscription "202". I would be so happy if that's the problem, and you, Rainer , were right again.

Hi Rainer, I can probably confirm that the issue is resolved. We replaced relay 202 in the fuse box (the label inside the box still indicates that it's for the glow plug and diesel systems), as well as relay number 219 on the engine control unit. It has now been running for 10 minutes without any problems. Hopefully, that's it.

I've uploaded some pictures of the two relays. I think the black relay 219, which is located in the water container near the engine control unit, looks suspicious, especially at the contacts.

Thank you for your time and your help!

Have a nice weekend!

Thank you for the feedback!

It looks like it's getting pretty hot inside; you could open it up.