Performance issues AHF / Vagcom log files

Hello,

Due to ongoing performance issues with my AHF (likely referring to an engine component), I purchased an adapter from Maik and connected it to my VAGCOM diagnostic tool to log some data. Here are some excerpts from the log files with the noteworthy values. Unfortunately, I don't have my own URL to offer complete files for download.
Perhaps I can send the logs to one of you to review and evaluate.

Okay, just a quick note about the performance issues. The engine ran perfectly until around 70,000 km. At around 50,000 km, a chip from *** (130 hp) was installed, which provided great acceleration (from around 1600 rpm, the car really took off; you almost only needed 5th gear). Smooth operation, impressive performance (linear power increase up to 4000 1/min), maximum speed of 205 (limited by engine speed).
At approximately 70,000 km, the engine performance suddenly dropped (estimated at around 20%): later onset and reduced torque (at around 1900 rpm), the engine felt sluggish when revving, the power increase up to 4000 rpm was less pronounced, and the reduction in fuel injection after 4200 rpm (which previously caused a sudden drop in power) was less noticeable because the engine was already lacking power beforehand. Unfortunately, all the checks of the Lmm (mass airflow sensor), fuel filter, etc., and the visit to the VW specialist have yielded no results.
At approximately 90,000 km, there's a noticeable loss of power, with a reduction in torque in the lower RPM range (1900-2200 RPM). The acceleration test showed that the times for 0-60 mph are on par with a well-maintained 110 hp engine, but too high for a 130 hp engine (perhaps someone has compared these values to a chipped 110 hp engine). The current top speed is 202 (indicated on the speedometer). It's difficult to describe in words how the engine feels. That's why there's Vagcom, unfortunately, I don't have any target values for a chipped AHF (air handling unit).

'I've noticed the following regarding the values: In group 11 (while driving in 4th gear), the actual turbo pressure takes a bit too long to reach the target value in the lower RPM range. However, full throttle was only applied at 1500 RPM, so the delayed build-up could also be due to that (which would also explain the low duty cycle).'
1 pulse/minute / required / is / keying rate.
1617 1795 1459 27.1
1743 1836 1938 55.8
1869 1918 2030 60.2
1995 1948 2020 62.6
2142 1989 1969 61
2268 1989 1948 61.4

The turbocharger's overboost pressure remains at approximately 1000 mbar across the entire RPM range, even though the boost pressure was increased to 1.2 bar according to the approval certificate (ABE). Around 3200 RPM, the actual value remains approximately 10-20 mbar below the setpoint, which is not critical.
I'm just wondering why the displayed target pressure is only 1 bar above atmospheric pressure?
At 4600 RPM, the actual pressure is still 0.9 bar.

Group 8/9 exhibits the lowest torque limit at 4300 RPM. Unfortunately, no values are appearing for the actual injection quantity in the log file. During the test run, these values corresponded to the lowest values from group 8.
Group 10, air mass is within the target range based on data from the error database.

Unfortunately, the logging for group 3/4 didn't work correctly, but the pre-heating of the oven is functioning, and I've observed maximum temperatures of 16°C before the oven heating.

Overall, the values appear to be quite normal. The actual values are generally within the expected range. So, the mechanics seem to be fine. However, I'm wondering if the control unit itself might be faulty and setting incorrect target values. Is that fundamentally possible?

I'm grateful for any opinions, and perhaps someone even has performance data from a chipped AHF that we could compare.

Thank you in advance.
It greets.
Jeans.

Hello,

The values for the boost pressure seem quite standard.
If you're not experiencing any issues with fuel delivery or a tilted catalytic converter (which is blocking the exhaust), and all the other values are within the acceptable range, then I'm at a loss.

Are you sure the chip is still installed and that no one has "taken advantage" of the customer service?

Best regards, Rainer.

Hello Rainer,

As I mentioned, I proactively replaced the diesel filter, but that didn't make any difference. However, I'm not sure about the condition of the strainer in the tank. How can I check it? I tentatively tried sucking on the suction line with my mouth. It was relatively easy.
I am mainly surprised that the values required by the control unit for the turbo pressure are so low.
Here are the values again from groups 8 and 1.

1 injection per minute per driver / torque limit / smoke limit / actual injection quantity.

2163 47.4 42 43.2 42
2226 47.2 42 43.2 42
2289 47.2 41.8 43 41.8
2352 47.2 41.8 43 41.8
2436 47 41.6 43 41.6
2499 47 41.4 43 41.6
2562 47 41.4 43 41.4
2625 46.8 41.2 42.8 41.4
2667 46.8 41.2 43 41.2
2730 46.8 41.2 42.8 41.2
2793 46.6 41 42.8 41
2856 46.6 41 42.6 41
2919 46.6 40.8 42.4 40.8
2961 46.6 40.8 42.4 40.8

'Even here, the values are surprisingly within the normal range for AHF. Given the chip, I would have expected values closer to those of ASZ. How is this possible?' Is it possible that there is a fault in the control unit?

enigmatic greetings.
JEan

Edit: I just checked the vacuum line again with the help of a friend for any air bubbles. And sure enough, when I briefly rev the engine in neutral, a continuous stream of small bubbles forms. As I mentioned before, I had already disconnected the vacuum line before the filter and blown into it -> no pressure escaped, so I think the check valve and the line are reasonably airtight. So, how can I check if the filter in the tank is clogged, and how can I verschandeln it?

Kruegerjean wrote:

1 injection per minute per driver / torque limit / smoke limit / actual injection quantity. 2163 47.4 42 43.2 42 2226 47.2 42 43.2 42 2289 47.2 41.8 43 41.8 2352 47.2 41.8 43 41.8 2436 47 41.6 43 41.6 2499 47 41.4 43 41.6 2562 47 41.4 43 41.4 2625 46.8 41.2 42.8 41.4 2667 46.8 41.2 43 41.2 2730 46.8 41.2 42.8 41.2 2793 46.6 41 42.8 41 2856 46.6 41 42.6 41 2919 46.6 40.8 42.4 40.8 2961 46.6 40.8 42.4 40.8 "Interestingly, the values here are within the normal range for AHF. Given the chip, I would have expected values closer to those of ASZ." How can that be? Is it possible that there is a fault in the control unit?

Hi.
It almost looks like the chip somehow reverted to its original factory settings, because the torque limitation is roughly normal for a stock 110.

It really seems likely that this happened during a customer service interaction.
Was that timing appropriate?
Would you be able to recognize your engine control unit (if it has been replaced)?

Previously, there were arguments against chip tuning, claiming that the modified software could be overwritten by the normal data sets during a routine check .
But I have no idea what's true about it, or which types of motor vehicles might be affected.

hello,

'The timing of the engine control unit replacement doesn't seem right. I can't imagine that's what happened, even with my VW dealer. They're not as knowledgeable as one might hope when it comes to complex questions, but otherwise, they're quite reputable. The chip installation was also done through the VW dealer. They removed the engine control unit, sent it to ***, and then reinstalled it. Could it be that the engine control unit is entering a kind of emergency mode, which would cause a significant loss of power in unmodified vehicles? However, this might not be as noticeable because the power output now falls within the standard range?' It should then be displayed in the error memory and be recognizable by the illuminated preheating lamp.
'Based on the values I'm seeing, the amount of fuel injected based on the driver's preference seems too low (and is also within the upper end of the standard range). An additional 20 horsepower would represent approximately an 18% increase in power, which would also require a minimum of 18% more fuel injection based on the driver's preference.' Could there be a fault in the electronic throttle that is affecting the engine control unit?
Does accessing the engine control unit (ECU) myself affect the warranty?
*** offers a 50,000 km warranty on the engine and other components after installation. I will contact *** directly to see if they are aware of this issue.

Otherwise, I remain grateful for any suggestions you may have.
Greetings.
Jean.

Hello,

Have you tinkered with the coding of the engine control unit (automatic transmission)?

Best regards, Rainer.

Hi,

I haven't made any changes to the coding; I connected the VAGCOM for the first time the day before yesterday. And it didn't just change on its own, did it?!

An initial inquiry to *** revealed the following, among other things:

Is the control unit or the software contained within it actually defective?
If the car is either damaged or incorrectly programmed, it will usually no longer function. In
In the few remaining cases, there are drastic symptoms, such as emergency procedures.
sporadic stalling, confusing error messages, and errors in the error memory were reported.
Since such signs are not present, a control unit or...
To reliably rule out software errors. Sure, here's the translation:

'Also, let's proceed.'
Partial deletion or modification of the data is technically not possible.
Based on your description, I suspect a defect in the control unit, or...
it could be due to a software issue or a programming error.



The *** technician is considering a faulty mass airflow sensor as a possible cause.
However, in my opinion, there's a reason to question this, as the torque limitation already prevents the injection quantity from increasing further. According to ***, the air mass for tuned vehicles must be at least 100 mg/h higher than the standard value, but according to values from group 10, this is roughly achieved. (With slight compromises, which may be due to the high outside temperatures of 28°C).

mass air flow / engine speed
630 1617
900 1743
995 1869
1000 1995
990 2142
965 2268
970 2415
950 2541
960 2667
955 2793
945 2919
930 3129
910 3255
890 3360
870 3444
865 3549
860 3633
850 3717
845 3801
840 3885
835 3969
830 4032
820 4116
815 4179
805 4242

The airflow decreases to a slightly greater extent in relation to the boost pressure. (At 4242 RPM, the absolute boost pressure is still 1999 mbar.)
Does that give any indication?

Greetings.
Jean.



















Perhaps I should go back to the friendly staff with the logged data. However, I also don't want to spend €60 an hour on fruitless troubleshooting.

Hello,

The readings for the mass airflow sensor seem normal to me.

Best regards, Rainer.

Hello,

Please provide the values for the engine control unit (ECU) ID and the coding of the engine control module.
I'm also assuming that you checked the error memory and it was empty?

hello,

Error memory is empty. The following data is displayed for the control unit:

Part Number: 038 906 018 BM
Soft coding: 00002

Component reference: 0000SG2115
Workshop number: WSC00046

I just received another email from ***. He could or would not provide detailed specification tables, only general information:

The values of the LMM should be at the upper limit, but at a minimum they should be...
100mg/h above the minimum batch value; that would be 850mg/H or more.
The same applies to the charging pressure, plus 100 mbar, which results in 1900-2400 mbar.

Therefore, it seems that the air mass is indeed a bit too low. However, the target boost pressure isn't exactly high either.

Okay, I have another question about the strainer located at the beginning of the inflow line in the tank (even though it's probably not the cause of the performance loss). How can I determine if it's clogged, and if so, how can I verschandeln it? As mentioned before, I'm experiencing slight bubbling when briefly revving the engine while it's idling.


Greetings.
Jean.

Hello,

Unfortunately, not much progress has been made in solving the problem. I have managed to resolve the bubbling issue in the inflow pipe. The gasket at the connection point of the return line, which is inserted into the diesel filter, was no longer in the best condition.
Unfortunately, it didn't change anything about the performance issue.

By the way, I just had another thought. Could it be possible that the electronics in the accelerator pedal are malfunctioning and sending an incorrect signal to the control unit, indicating a lower-than-desired fuel injection amount, which in turn results in lower-than-expected turbo boost pressure?
Unfortunately, I'm not very familiar with the signal sequence within the control unit. From which input signals is the torque limitation calculated? If the torque limitation also depends on the driver-requested fuel injection amount, then this could be a source of error. If the setting is only related to the speed, then that option is obviously not available.
Thank you for your opinions.

Greetings.
Jean.

Kruegerjean wrote:

Could it be possible that the electronics in the accelerator pedal are malfunctioning, and are sending the engine control unit a signal indicating a lower-than-desired fuel injection amount, which in turn results in a lower-than-expected turbo boost pressure?

Hello Jean,

You could read this out using VAGCOM. For example, with the AFN engine, you can find the pedal position displayed in measuring block 002, among other things: Idle = 0%, full throttle should be 100%. Can you also check it with the engine idling (with the ignition on, of course)?

Quote:

If the torque limitation also depends on the driver-requested fuel injection amount, then this would be a potential source of error. If it were to be determined solely based on the speed, then that possibility would naturally be ruled out.

The torque is definitely independent of the pedal position.
It's possible that the emergency stop function is implemented via the motor drive, but as far as I know, this hasn't been definitively clarified yet.