TT5 2nd Gear Slipping: Common Causes & Fixes

"After changing the transmission oil and tightening the drain plug, I feel that my second gear is slipping for a very long time. Sometimes, when I try to accelerate quickly and it shifts into second gear, it engages properly and pulls forward, but more often it just slips and doesn't really gain speed. You don't really feel any power. Also, when I'm in fifth gear at 130-140 km/h and use the kickdown, which shifts it to fourth gear, it slips for a very long time before it finally engages and provides power. I have a 2.5 V6 TDI AFB, manufactured in 1998. I know that my mass airflow sensor (MAF sensor) is completely broken, I would say, because I experience wavy acceleration and it revs very high in the red zone for a long time during kickdown before it finally shifts to the next gear. Also, on the highway, it's limited to 195-200 km/h, and it revs very slowly, starting around 140 km/h. Could the shifting problem be related to the MAF sensor because it's providing incorrect readings?"

Hello Rico_avant,
New LMM? Then you know it - or do you want to drive with so little power?
How is it supposed to rev up and shift if it's lacking power?

Okay, so I installed the new mass airflow sensor today, and at first, everything seemed great – no more unnecessary hesitation. But then, when I use the kickdown, it revs very slowly starting at 4000 RPM, and it reaches the rev limiter very slowly. Also, going slightly uphill, it stays at 140 km/h and doesn't accelerate any further.
I did some measurements and noticed that the MAF (Mass Air Flow) values suddenly drop from 965 to 549 at 3900 RPM, regardless of the gear. That's why I can't use the kickdown. What's going on? At the same time, I'm now getting the error code "MAF sensor short circuit to positive." It can't be that the new MAF sensor is defective, can it? The old one also had this error. Could there be a problem with the wiring? Why do the values suddenly drop at 3900 RPM?

Is the car chipped? Has the turbo boost been adjusted? Have you ever logged any data from it?

Regards,
Guste.

So, it was the mass airflow sensor (MAF sensor) that was defective, and I finally found one that works .
"I noticed that after not driving with tiptronic for a long time, when I'm in second gear and accelerate in tiptronic mode, it's much more fun because there's almost no slippage, and my engine then pulls forward very nicely and powerfully. However, when I'm in 'D' mode, I don't feel the same direct driving experience, and there's a lot more slippage from the torque converter. Is this normal, or should it accelerate just as well in 'D' without slippage? I feel like it's keeping the clutch open or the torque converter engaged for too long in 'D'. What can I do to make it accelerate as well in 'D' as it does in tiptronic? The transmission fluid and filter are new, and the problem existed before and after the change. But as I said, this only happens in second gear; the other gears engage properly in both 'D' and tiptronic mode."
Hab festgestellt nachdem ich lange nicht auf tiptronik gefahren bin das wenn ich den 2.Gang drin habe und im tiptronikmodus aufs gas gehe es fiel mehr spass macht da eigentlich fast garkein schlupf da ist und mein AFB dann sehr schön und kräftig nach vorn geht. Habe ich allerdings auf D stehen dann ist nicht so ein direktes fahrverhalten zu spüren,viel mehr Schlupf vom Wandler.muss das so oder müßte er bei "D" auch so gut abgehen ohne schlupf? Hab das Gefühl wenn er auf D steht lässt er die kupplung zu lange offen bzw.den wandler. Was kann ich tun damit er auf D genauso gut packt? Getriebeöl mit Filter sind neu,Problem war vorher und nachher. Aber wie gesagt das ganze nur im 2.gang die anderen gänge packen immer ob D oder TiptronikmodusHab festgestellt nachdem ich lange nicht auf tiptronik gefahren bin das wenn ich den 2.Gang drin habe und im tiptronikmodus aufs gas gehe es fiel mehr spass macht da eigentlich fast garkein schlupf da ist und mein AFB dann sehr schön und kräftig nach vorn geht. Habe ich allerdings auf D stehen dann ist nicht so ein direktes fahrverhalten zu spüren,viel mehr Schlupf vom Wandler.muss das so oder müßte er bei "D" auch so gut abgehen ohne schlupf? Hab das Gefühl wenn er auf D steht lässt er die kupplung zu lange offen bzw.den wandler. Was kann ich tun damit er auf D genauso gut packt? Getriebeöl mit Filter sind neu,Problem war vorher und nachher. AbAs I mentioned, this only happens in second gear; the other gears always engage properly, whether in "D" or "Tiptronic" mode.
As I said, everything is original, no modifications or chips. The previous owner had a "Speedbuster" chip installed for 180 horsepower, but now everything is back to its original state.

Okay, I've been browsing the forums again and found something. Apparently, a solenoid valve located in the valve body of the transmission is failing, which is preventing it from engaging properly. It seems to be an electrical problem rather than a mechanical one. What do you think about that?

Does anyone have any other ideas about this?

Error codes read?
Possibly recode the Tiptronic.
I have reconfigured mine to be in power-saving mode.
which has the advantage of having less slippage in the gears when shifting.
Because slippage is wasted energy.

@tagessuppe:
Could you please post the encoding you mentioned with less 'slop'?
Thank you!

I encoded it as 00111, but the middle '1' is now irrelevant since the DSP is inactive.
Therefore, 00011 should have the same effect.