Wastegate actuator adaption CXEB

[Deansie]

Meanwhile - it seems that we can run the G581 into different position via engine's Basic Settings > IDE00457 - Test of turbocharger. Test runs for 60 seconds sweeping the actuator a couple of times.

View attachment 262393

View attachment 262392

However, I'm not sure if OBDeleven can make a log while test is running. At least in the past it didn't have the capability.

[T6_measured] 01-Engine - Built-in tests for turbocharger

HOW-TO run engine's built-in test for turbocharger Engine running VCDS > Select > Engine > Basic Settings > IDE00457 - Test of turbocharger Select "Measuring Values" Pick up e.g. the following data items for monitoring: IDE00021 Engine RPM IDE07375 Charge pressure before throttle valve...

www.t6forum.com

Wow, thanks!

This is giving me alot of more hope! I spoke to my tuner that would let me use his VCDS if I wanted to. The thing is I have to drive the van 35km to do so. If the new N75 makes no difference I know exactly know what rabbithole to go down.

 

[Deansie]

Meanwhile - it seems that we can run the G581 into different position via engine's Basic Settings > IDE00457 - Test of turbocharger. Test runs for 60 seconds sweeping the actuator a couple of times.

View attachment 262393

View attachment 262392

However, I'm not sure if OBDeleven can make a log while test is running. At least in the past it didn't have the capability.

[T6_measured] 01-Engine - Built-in tests for turbocharger

HOW-TO run engine's built-in test for turbocharger Engine running VCDS > Select > Engine > Basic Settings > IDE00457 - Test of turbocharger Select "Measuring Values" Pick up e.g. the following data items for monitoring: IDE00021 Engine RPM IDE07375 Charge pressure before throttle valve...

www.t6forum.com

Turns out the voltage reading on the G581 at 700mbar equals…


Am pretty sure we just found the culprit!

 

[Deansie]

Would have been great if this had been the solution... The reason for the voltage to halt at 1.769v is because the valve (?) inside the turbo seems stuck from opening any further. I came to this conclusion since the arm from the vacuum unit is not adjustable when it is "original". I have a refurbished bi-turbo and they haven't changed this unit.

My first instinct was to put a whole lot of penetrating lube (5-56) on the piece sticking in to the turbo and ventilate the arm with vacuum on the vacuum unit. However, this didn't make any difference and I'm wondering what the heck happened in there whilst I was driving.

What is the purpose of this unit? There are three vacuum units on this turbo, clearly not all of them can be wastegates. How would one even go about to inspect this issue without removing the turbos again? I'm all open for ideas..

Edit: On further investigation I seem to find that the physical movement on the arm is within reasonable range (in comparison with the G580 witch has a much larger range), therefore I'm speculating that the position sender is sending the wrong voltage to the ECU. Maybe this could be the case if a Boost Control Module is faulty (N75?). Will replace it in the morning and see if there is any difference.

 

[Deansie]

Stuck VNT, will assemble and go out for a hard drive monitoring the voltage and hopefully get it to unstick.. bullox on a ”refurbed” turbo.

 

[mmi]

the arm from the vacuum unit is not adjustable

I believe it is - just need to remove the vacuum unit to adjust.
Check this thread -

Help please Flashing coil light and EML on. Multiple codes 31391 27202 8208 8216 8217 8338

I see they give you a few circlips as I’d imagine this will be the part that provokes the most swearing!

www.t6forum.com

What is the purpose of this unit? There are three vacuum units on this turbo, clearly not all of them can be wastegates.

Neither of units discussed this far is the wastegate. The wastegate is the third one at the bottom of turbo complex.

G580 is turbine changeover valve (an exhaust flap) between the two turbos. G581 is the one adjusting charge pressure - operating the turbo vanes.
More details in Forum downloads -

SSP 564 - The T6 2.0L TDi

VW Self Study Programme, Document 564 - The 2.0 litre TDI Engine In The T6 The introduction of modern, particularly efficient Euro-6 engines represents a central feature of the new T6. All units are equipped with Blue Motion Technology as...

www.t6forum.com

 

[Deansie]

I believe it is - just need to remove the vacuum unit to adjust.
Check this thread -

Help please Flashing coil light and EML on. Multiple codes 31391 27202 8208 8216 8217 8338

I see they give you a few circlips as I’d imagine this will be the part that provokes the most swearing!

www.t6forum.com

Neither of units discussed this far is the wastegate. The wastegate is the third one at the bottom of turbo complex.

G580 is turbine changeover valve (an exhaust flap) between the two turbos. G581 is the one adjusting charge pressure - operating the turbo vanes.
More details in Forum downloads -

SSP 564 - The T6 2.0L TDi

VW Self Study Programme, Document 564 - The 2.0 litre TDI Engine In The T6 The introduction of modern, particularly efficient Euro-6 engines represents a central feature of the new T6. All units are equipped with Blue Motion Technology as...

www.t6forum.com

Unfortunately the vacuumunit isn’t adjustable, it’s just the new sparepart that can be adjusted. Trust me, I tried in every way possible until I saw under magnification that the rod is solid without threads.

However, this wouldn’t have done any difference since the arm to the VNT is partially stuck, hence the high voltage with the ignition on. Have managed to exercise the arm quite a bit and am down to around 1.3v at the moment. This in turn with the also changed out N75 have allowed me to run the van a small bit without any fault codes popping up. Will keep an eye out on the voltage every now and then, and if error still occurs I found that other TDI-owners have managed to clean the VNT mechanism with Mr Muscle oven cleaner and gotten a good result.

Don’t understand why the repairshop where I bought the replacement turbo havent refurbed the vanes or even cleaned them, but will ask for a partial refund.

Thank you kindly for all help!

 

[Deansie]

Still having som troubles with my VNT, upon very low boost (cruising) and after throttle off from a high boost accelleration their often comes up a fault code p00af00 indicating issues with the performance of the actuator for the VNT.

Have managed to exercise the arm with good outcome but I can’t figure out what the numbers should be.

As is right now, I can get as low as 18,89% (then a complete stop) up to 100,52% (then a complete stop) with the arm and its now running smoothly. Still havent tried the ovencleaner hack yet, and will save it as a last outcome!

18,89% indicates circa 4,1v
100,52% indicates circa 1,3v

Workshop manual states 0,75v, but what does the offset mean in provided images?

If I still get a fault code in regard this, am I barking up the wrong tree or what?

 

[mmi]

Workshop manual states 0,75v, but what does the offset mean in provided images?

I don't know how the ECU calculates the offset.
However, found in logs (total of 8 hours engine running) the offset vaying just slighly from -2.46% to -1.17%

The same logs had
IDE07783 Turbine actuator 1 bank 1: posit.feedback - Raw voltage --- varying from 0.801 to 3.694 Volts
IDE07785 Turbine actuator 1 bank 1: posit.feedback - Actual value --- varying from 100.39% to 21.64% respectively

 

[Deansie]

I don't know how the ECU calculates the offset.
However, found in logs (total of 8 hours engine running) the offset vaying just slighly from -2.46% to -1.17%

The same logs had
IDE07783 Turbine actuator 1 bank 1: posit.feedback - Raw voltage --- varying from 0.801 to 3.694 Volts
IDE07785 Turbine actuator 1 bank 1: posit.feedback - Actual value --- varying from 100.39% to 21.64% respectively

Thank you! Then the offset indicates that the voltage-range on my van is about 12-13% offset from the workshop manuals figures, maybe this is due to my van being tuned since your offset is lower.

I

 

[Deansie]

I don't know how the ECU calculates the offset.
However, found in logs (total of 8 hours engine running) the offset vaying just slighly from -2.46% to -1.17%

The same logs had
IDE07783 Turbine actuator 1 bank 1: posit.feedback - Raw voltage --- varying from 0.801 to 3.694 Volts
IDE07785 Turbine actuator 1 bank 1: posit.feedback - Actual value --- varying from 100.39% to 21.64% respectively

Here is the part that is really odd. Right before I get the flashing coil light (p00af00 Performance) and in conjunction with a real acceleration pull, I can observe the requested value from the ECU at 5%, meaning that it wants the VNT to be almost fully open but in reality it bottoms out at around 20%.

Since there is too big of a difference from actual and requested value a fault code is set and the van is put in limp mode, until next restart of the vehicle.

Big question is why?! Du you also get a request of 5% from your ECU (even though its not logged?) or has my tuner messed up my map?

 

[mmi]

the requested value from the ECU

I guess you mean these -
IDE07784 Turbine actuator 1 bank 1: posit.feedback - Specified value (=requested)
IDE07785 Turbine actuator 1 bank 1: posit.feedback - Actual value

Big question is why?! Du you also get a request of 5% from your ECU (even though its not logged?)

It seems that I do get the 5% requests.

Below a log snippet where pulling uphill (actually twice: 1602...1612 seconds and 1624...1629 seconds).
- at 1611 and 1629 seconds the requested (light blue) indeed "peaks" down at 5% but the actual (dark blue) saturates at 18%.

IDE07786 Turbine actuator 1 bank 1: posit.feedback - Offset closed
This one (green) seems to vibrate around zero though.



Sorry about not so good sampling rate above (only 2 samples/second) but this is my daily recording setup.

Below a VCDS log snippet (but without the requested by ECU actuator position).
The actual value (red) saturated at 18% (it's the same vehicle).

 

[Deansie]

I guess you mean these -
IDE07784 Turbine actuator 1 bank 1: posit.feedback - Specified value (=requested)
IDE07785 Turbine actuator 1 bank 1: posit.feedback - Actual value


It seems that I do get the 5% requests.

Below a log snippet where pulling uphill (actually twice: 1602...1612 seconds and 1624...1629 seconds).
- at 1611 and 1629 seconds the requested (light blue) indeed "peaks" down at 5% but the actual (dark blue) saturates at 18%.

IDE07786 Turbine actuator 1 bank 1: posit.feedback - Offset closed
This one (green) seems to vibrate around zero though.

View attachment 263463

Sorry about not so good sampling rate above (only 2 samples/second) but this is my daily recording setup.

Below a VCDS log snippet (but without the requested by ECU actuator position).
The actual value (red) saturated at 18% (it's the same vehicle).

View attachment 263465

Thank you very much! Will get the tuned software removed tomorrow to see if this cures the issue I am having since the figures seems quite similar to yours except the offset.

If this doesn’t work, how would one go about to measure up the actual positioner on the actuator?

 

[Deansie]

Ok, so I got the tuned software removed but the voltage didn’t change. However, the drive home (35km) went flawless så I figured it indeed was the tuning that messed up the signal some how.

This theory was short lived, since the next startup the car went into limpmode att about the same conditions as earlier. The tuner theorised that when uploading new software all the adaptations was reset cause the van to initialize new adaptations, hence no issues on the first run. But as soon as the adaptations conditions werent met, the issues continued.

Will recieve a new actuator from the turbo rebuilder to see if this fixes the range of the voltage and hopefully solve the problem.

 

[mmi]

The tuner theorised that when uploading new software all the adaptations was reset cause the van to initialize new adaptations, hence no issues on the first run. But as soon as the adaptations conditions werent met, the issues continued.

Did you or the tuner (ever) run the engine's basic settings - Adaptation of turbocharger?
I'm not sure what it actually does as on my engine it's not doing much as it's obviously quite well aligned. Certainly would be interesting to see if the adaptation fails on yours - possibly because of the voltage mismatch.


Have you checked if there is also under "more normal" conditions any mismatch between:
a) requested and actual charge pressure?
b) requsted and actuator position?

Meanwhile, below a snippet from my "test track" - driving using cruise control (set to 85 km/h = 1500 RPM) to provide repeatable conditions - againt an uphill at varying slopes. The uphill isn't steep but provides a decent stable loads.

The requested and actual values seem to overlap perfectly



From marker to marker it's 3.4 km with approx. 66 meters elevation difference (calculated as 8 meters/mbar)

 

[Deansie]

Did you or the tuner (ever) run the engine's basic settings - Adaptation of turbocharger?
I'm not sure what it actually does as on my engine it's not doing much as it's obviously quite well aligned. Certainly would be interesting to see if the adaptation fails on yours - possibly because of the voltage mismatch.
View attachment 263596

Have you checked if there is also under "more normal" conditions any mismatch between:
a) requested and actual charge pressure?
b) requsted and actuator position?

Meanwhile, below a snippet from my "test track" - driving using cruise control (set to 85 km/h = 1500 RPM) to provide repeatable conditions - againt an uphill at varying slopes. The uphill isn't steep but provides a decent stable loads.

The requested and actual values seem to overlap perfectly

View attachment 263597

From marker to marker it's 3.4 km with approx. 66 meters elevation difference (calculated as 8 meters/mbar)
View attachment 263598

If I recall correctly I ran the ”Adaptation of turbocharger” just after the swap and with the eng/on it failed with the message ”Exited due to safety reasons” but when I ran it with the engine off/ign on it finished.

Tried to run it yesterday with the engine on and I got the same message ”Exited due to safety reasons”, this seems to come down to the voltagerange being to far off? And I don’t think it does anything really with the engine off/ign on rather than giving a thumbs up.

Will try and put together some charts, I havent done so since I’m on a Iphone but will bust out my crappy Android and chart it.

I can’t seem to find any ticker on Live data for requested charge pressure, only the actual value. Don’t know why it’s not present in the list when using OBD11. Other than that the positioner value from requested and actual is very similar until full throttle when the actual stops at about 18% and the requested is at 5%.

I did however notice something today that right when i push the throttle from cruising at say 70km/h the voltage dips a little before it rises, will try to illustrate.

2.1v - 2.1v - 1.8v - 1.6v - 2.1v - 2.8v - etc
—Cruise——-Throttle————-

As if there was to high of a vacuumpull? Did tap in right between the checkvalve and the vacuumpump and when I turned on the engine I got around -930mbar of negative pressure. Don’t know if this is normal or not! The negative pressure moved from -930 —> -400mbar when giving a little enginerev.

 

[mmi]

I can’t seem to find any ticker on Live data for requested charge pressure, only the actual value. Don’t know why it’s not present in the list when using OBD11.

Should be labeled as "Charge air pressure specified value" When you checked was it the tuned software or the stock one?

 

[mmi]

Behind the scenes correspondence brought public- to keep the thread consistent, and hopefully useful if/when other members face the same/similar issue.

Now I received the file.

Possibly the issue was a kind of missing time stamps for data - I just numbered the lines 1, 2, 3, ....

Anyways, a few quick ones

Minimums and maximums of the data
View attachment 263714

Quite a boost you are getting - 3.8 bars - but specified only 3 bars!
View attachment 263716


Strange that the actual position is not following the specified all the time - at marker 155-165.
View attachment 263717

The Voltage curvature follows nicely the "Turbo Act" - naturally. But as "Turbo Act" runs from 19.64 to 100% makes me wonder if the adaptation has taken care of the scaling. And the actual issue would just be why the actual position can't follow the specified????? Confusing part is the behaviour of the pressure then - not following the actuator position?

View attachment 263718

Wow! You my friend, are magnificent!

Hmm, what if it still is the VNT that isn’t responding quite as expected? Like, partially sticking at marker 155-165?

Would it be doable to separate the turbo and inspect the VNT-mechanism without removing it from the van? And whitout parts scattering all around when opening?

Forgot to mention that the van ran perfectly without any fault codes popping up this last ride. Like, what in the world? Obviously there is something bothering it though, seeing the charts.

Well, it looks like something is sticking. Have you checked the "Charge pressure control solenoid valve (N75)"?


I don't know - sounds a bit scary.


Did you do exactly the same? Or is it just "almost" good.

N75 is new from Pierburg!


That’s what I thought.


Yup, drove as I’ve done most of the times and it felt like it more or less like before the swap… a little hesitation on the throttle though. The data in your chart is from this ride and a bit of a bumler that no code showed up.

That's then eliminated.

Would be nice if could run the Turbocharger test and record the position to see if it ever sticks then.
However, my impression is that OBDeleven doesn't do both simultaneously?

That seems to be the case unfortunately, will investigate!

I could record the movement with camera?

---

Here is the complete log from my drive yesterday, don’t understand why the datafeed stopped showing on the recording. Maybe another clue?

Perhaps the OBDeleven "crashed" at 688.19 seconds - after that there are no changes in the data. Also sampling rate changed at that moment.
Before sampling rate was in average 0.19 seconds/dataline, thereafter 0.37 seconds/dataline. Also here and there are 5 second pauses (vertical lines below).

View attachment 263783

Makes sense since it was a very low end Android-device running the app! Unfortunately I didn't get around to do the turbocharger test today but will return to you tomorrow! Maybe we should take the conversation out to my thread again in case other people stumble upon the same issue in the future?

 

[Deansie]

Behind the scenes correspondence brought public- to keep the thread consistent, and hopefully useful if/when other members face the same/similar issue.

Here is a snippet from the turbocharger test!

IMG_4576.mov är tillgänglig för nedladdning

Klicka för att gå till nedladdning av IMG_4576.mov (63.9 MB) med TransferNow

www.transfernow.net

 

[Deansie]

Hoping to receive a new VGT-actuator from the company that rebuilt this turbo no later than next week. Will update with results on the voltage-reading once it's installed.

Been driving the van for a few days now with OEM software without any tune and no fault code has shown up yet, though I'm pretty sure there still is a issue with the turbocharger adaptation since it won't run "Due to safety reasons". Hopefully the new actuator resolves it and I can get it tuned again and hence end this nightmare.

 

[Deansie]

Did you or the tuner (ever) run the engine's basic settings - Adaptation of turbocharger?
I'm not sure what it actually does as on my engine it's not doing much as it's obviously quite well aligned. Certainly would be interesting to see if the adaptation fails on yours - possibly because of the voltage mismatch.
View attachment 263596

Have you checked if there is also under "more normal" conditions any mismatch between:
a) requested and actual charge pressure?
b) requsted and actuator position?

Meanwhile, below a snippet from my "test track" - driving using cruise control (set to 85 km/h = 1500 RPM) to provide repeatable conditions - againt an uphill at varying slopes. The uphill isn't steep but provides a decent stable loads.

The requested and actual values seem to overlap perfectly

View attachment 263597

From marker to marker it's 3.4 km with approx. 66 meters elevation difference (calculated as 8 meters/mbar)
View attachment 263598

Would you mind taking a look at another run I did today? Really appreciate your commitment!