Boost pressure overshoot: 1905 mbar / 1911 rpm at maximum torque (19-04-2008, 18:34)

Hello,
After today's test drive at the A3 service station with 97,000 km on the odometer, I noticed that under full load, I was experiencing brief but significant overboosts in turbocharger pressure. However, further along the route, the actual values matched the target values.
LLM ist nagelneu. Es kann ja auch sein das, dass VTG-Gestänge lahmt oder ausgeleiert ist? Das AGR scheidet ja aus, da bei Werte ab 1386 rpm 100% Gaspedalstellung. Dieses ausbremsen des Laders bemerkt man auch beim Fahren durch kurzeitigen Leistungsverlust. Natürlich könnte es auch an den modifizierten Datensatz liegen. Weiß nicht ob dies normal ist, da ich keine Vergleichswerte habe. Vielleicht könnt Ihr mir ja bei der weiteren Fehlersuche/Diagnose weiterhelfen. VieYou're very welcome!

Here are my logs (ambient air pressure: 938 mbar).
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Dear moderator, unfortunately, I posted this message in the wrong category; please move it to "Engine Control Units and Diagnostics," thank you.

Did the software somehow create a parking spot?

Best regards,

EMSimASZ wrote:

Did a parking spot tuner magically create this soft spot? best regards

How am I supposed to understand "Parkplatztuner" ?

Troubleshooting such issues in engines with unknown engine control unit (ECU) software is largely pointless because you can only determine where the "problem" lies with diagnostic equipment.

If you revert to the factory settings and still experience similar behavior, it's likely a hardware issue. However, I don't think that's the case here.

Best regards, Rainer.

Okay, I'll take a look at the VTG (Vehicle Transport Group). It seems that other people with similar overspeeding incidents have also reported them here. You are absolutely right, Rainer, that it will be very difficult with this dataset! I've added a link to my logs at the top.

Dear moderator, I unfortunately posted this message in the wrong category; please move it to "Engine Control Units and Diagnostics." Thank you. [Edit ulf: done]

ASZ-Fahrer wrote:

After today's test drive on the A3 at the ASZ station with 97000 km, under full load, I noticed that I have short-term, significant overboosts in boost pressure. Subsequently, actual values are equal to target values! The LLM is brand new.

It's possible that the VTG linkage is sluggish or loose? I want to rule this out with a 99% certainty, because the LD (longitudinal displacement) is reasonably well regulated after settling in, without the TV (transverse vibration) having to make the large jumps typical of worn-out mechanisms or VTG clamps.

Therefore, the high LD peaks are likely due to the "quirks" of your tuner, as is often the case.

Parallel example: http://www.ibiza-forum.de/index.php?page=Thread&postID=486735

Hello Ulf,

Thank you for your repeated confirmation of my problem .
I will probably have to solve this problem with a new, verschandeln dataset!

Rainer K. wrote:

Troubleshooting

such issues with effects on engines that have unknown engine control unit (ECU) software is quite pointless, as you can hardly determine where the :(error} lies without diagnostic equipment.

If you revert to the factory settings and still experience similar behavior, it's likely a hardware issue. However, I don't think that's the case here.

Greetings, Rainer}.

Hello Rainer,

I have now had my ASZ reflashed to its original firmware version.
I've added the new logs here.
I'm sorry, but I cannot translate that text because it appears to be a URL or web address rather than a piece of written content. To provide an accurate translation, please provide the actual text you would like me to translate.

Wie Ihr sehen könnt, leider immer noch LD-Peaks! IST 1812mbar vs. 1953 rpm, Soll 1365mbar ! Ich weiß, dass auch der Seriendatensatz LD-Überschwinger haben kann, meine sind dennoch ziemlich hoch! WeDoes anyone have any advice?

Furthermore:
During the last attempt to test a better dataset using a test drive, the FIS display suddenly showed "Diagnosis." After resetting it back to the standard mode, I performed an automatic error scan, which resulted in:

Address 01 -------------------------------------------------------
Control unit: 038 906 019 FT
Component: 1.9L R4 EDC G000SG 1527
Encoding: 00002
Workshop code: WSC 06435.
WAUZZZ8LX3A008506 AUZ7Z0B2114798
Two error codes found:
18058 - Data bus malfunction; no message received from the instrument cluster.
P1650 - 35-00 - -
17978 - Engine control unit locked.
P1570 - 35-00 - -
Readiness: Not available.

Address 03 -------------------------------------------------------
Control unit: 1C0 907 379 G
Component: ESP FRONT MK60 0101
Encoding: 0019970
Workshop code: WSC 06435.
"One error found:"
01314 - Engine Control Unit (ECU)
004 - No signal/communication - Intermittent.

Address 08 -------------------------------------------------------
Control unit: 8L0 820 043 L
Part number: A3 CLIMATE CONTROL UNIT 0105
Coding: 00043
Workshop code: WSC 06435.
"One error found:"
01582 - Coolant temperature sensor signal.
30-10 - Interruption / Short circuit after positive voltage - Occasional.

Address 15 - Airbags are not active.

Address 17 -------------------------------------------------------
Control unit: 8L0 920 932 D
Part: COMBINATION INSTRUMENT + ODOMETER. VDO D10.
Encoding: 04040
Workshop code: WSC 49859.
WAUZZZ8LX3A008506 AUZ7Z0B2114798
"One error found:"
01314 - Engine Control Unit (ECU)
49-10 - No communication - Intermittent.

Actually, the serial retrofit was supposed to eliminate the LD peaks, but now I have LD peaks and a full error memory }.

I would be very grateful for your assessment of my problem!

Best regards, Tobi.

Your tuner should be able to tell you where the errors are coming from and also be able to fix them.

There are plenty of technical articles available about the problematic VTG (variable transmission gearbox). It's also possible that someone has tampered with the VTG.
I'm leaning towards the first option, but given the strong underspin, I'm inclined to choose it.

Hello,
I can rule out anyone being involved with VTG; I was always there and aware of everything.
In the first attempt with my tuner, the LD (Lambda) was simply forced downwards, resulting in little power and persistent overshoot. In the second and final attempt, the LD was raised, which resulted in... even more power with a higher LD peak of 1990 mbar. During the test drive, the FIS (Instrument Cluster) displayed "Diagnosis," which I had never seen before! I suspect that it was in a limp mode. Therefore, I decided to switch back to the stock configuration. At home, I read out the error memory. I just hope that the MSTG (Motor Steuergerät - Engine Control Unit) is still okay .

If there are still such strong LD peaks in the standard state, it's not wrong to carefully examine the vacuum connections.
Due to a kink or restriction in the hoses and the control valve, the vacuum can only escape very slowly, which means that the VTG (Variable Turbine Geometry) adjusts back very slowly.

Steffarn wrote:

If there are still such strong LD peaks in the standard configuration, it is not wrong to carefully examine the vacuum connection. Durch einen knick, oder eine engstelle in den schläuchen und Taktventil, kann der Unterdruck nur sehr langsam entweichen und somit die VTG nur recht langsam zurück regeln.

I will investigate this further, as well as the valve timing gear (VTG) itself, to check for smooth operation!
First of all, thank you, Steffarn .

ASZ-Fahrer wrote:

During the last test drive, the FIS (multifunction display) showed "Diagnosis" while driving. I had never seen that before! I suspect it was in a limp mode. Then I finally converted it to the standard configuration. At home, I read out the error memory. I just hope that the MSTG (motor speed limiter) is still okay

. Everyone actually notices the limp mode because of the frightening lack of power.

A faulty MSG typically manifests with more severe errors than just noticeable LD overshoots.

If you didn't have such high overshoots before the tuning, there are essentially only two possibilities left:

The tuner flashed a wrong file as the "firmware," which may also cause strange error messages.

"Due to excessively high exhaust temperatures caused by tuning, you've damaged the hot side of your variable geometry turbocharger (VTG), and this is also affecting its performance at stock power levels."

Hello everyone,

I ran the valve travel gauge (VTG) in basic calibration mode using the MWB 11 device for 30 minutes and briefly recorded the data. The values I obtained match those that have been mentioned here before. Based on this, the VTG should be moving from stop to stop.

MKB: ASZ
Model: A3.
Year of construction: 06/2002.
Message No.: 038 906 019 FT
Default setting possible: yes.
Engine speed during the test (without acceleration!): 1407 RPM.
Maximum boost pressure: 1111.5 mbar.
Boost pressure min.: 936 mbar.

Even during visual inspection, the total travel of the valve was approximately 1 cm, moving smoothly and evenly from stop to stop.
The maximum value of the LD overshoot, which is 1762 mbar, consistently occurs at exactly 1950 rpm.

I have previously recorded data from measuring blocks 3.8 and 11, and I also observed that the EGR mass flow rate (mg/hub) exhibits highly variable values (see the difference between actual and target values). Due to the noticeable deviations in the EGR mass flow rate that I observed, I created another log of measuring block 3 while it was in its basic settings mode.
As mentioned before in this thread:

"With the EGR system deactivated, the air mass should be approximately... on a 1.9-liter engine at idle."

Quote:

"The displayed value is 450 mg per injection; with the EGR system active, it's approximately half that amount." Significantly different values indicate malfunctions in the EGR or mass airflow sensor area. Will the higher value for the inactive EGR system be reached? So, the membrane valve is not closing properly and/or the mass airflow sensor is providing too low readings. "Large variations in values for active versus inactive EGR systems indicate a stuck membrane valve."

With the EGR system deactivated, I achieve a maximum of 475 mg per injection; with the EGR system activated, I get a minimum of 176 mg per injection.
Well, it's becoming difficult for me to troubleshoot and find the cause of the problem.
Do I now have a stuck membrane valve or a malfunctioning VTG (Variable Geometry Turbine) that is responsible for the high LD (Load Dump) peaks?

I have updated all the logs. Please take a look at my problem and provide your feedback.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.


PS: I was already at the "friendly" mechanic who wanted to install a new turbocharger immediately without any diagnosis .

ASZ-Fahrer wrote:

I once logged the values for MWB 3.8 and 11, and also noticed that the EGR mg/hub shows highly variable readings (actual vs. target value, please see).

Due to the noticeable deviations in the EGR mg/hub that I observed, I created another log of MWB 3 in the basic settings mode.

Quote:

It's pointless if it's being driven at almost full load, which is evident from the air mass target value = 850 mg. The function of the EGR valve can only be tested under partial load, at approximately 3000 rpm, and within a pedal range of 0 to about 50%.

Is it now a stuck membrane valve or a hanging VTG that is responsible for the high LD peaks?} To me, the mechanics look okay, as explained in my previous post.
I still suspect a software issue: either an incorrect original file (I can't find a MSG 019FT anywhere in the entire record!), or a data state that is causing unexpected behavior. This occasionally happens.
A tuner who is truly familiar with the LDR within the EDC15 software could potentially provide a solution – like our colleague here.

It's conceivable, but in my opinion rather unlikely, that there could be a selective VTG (hot) clamping mechanism within the closed area of the VTG: this could explain the large overshoots by delaying the opening, but then, in the semi-open VTG range, the control system would operate normally.
This can be determined with a "nudge test": does the (warmed-up!) variable geometry turbine react sensitively to changes in control pressure even close to the closed position, or only jerkily and abruptly? If so, it would mean disassembling the turbocharger, cleaning the VTG, and possibly grinding down any areas that are prone to sticking.
Or should I install a new charger instead...

'038 906 019 FT is correct.'
Did the corporation cut funding, and was the number 038 998 019 discontinued due to various problems?