Transmission does this lunging when going into first

[rickr71]

I’ve done the dsg adaptation and it didn’t help. Trans still lunges 2 or 3 times before going to idle. Anyone else have this?
https://imgur.com/gallery/3KHUUCC

[qcrazy]

TCU tune? If so, who?

What did you follow for the adaptation?

[rickr71]

Yeah it has an APR TCU tune.
I used VCDS and the Ross tech web site for how to do it. The adaptation seems to have no impact on the issue. It was happening the same before the adaptation, so im thinking maybe its something else.
Ive had the tune(TCU and stage 1 ECU ) for over a year with no issues. Just last couple of weeks when dropping from 2nd into 1st gear or reverse to 1st gear and whether its D1 S1 or if i use manual it all does the same thing.
It sort of bounces from 500rpm tp 1200 almost like someone is momentarily hitting the gas pedal and then letting off. It does about 5 cycles of this and then resumes a normal idle

[joserod92]

Yeah it has an APR TCU tune.
I used VCDS and the Ross tech web site for how to do it. The adaptation seems to have no impact on the issue. It was happening the same before the adaptation, so im thinking maybe its something else.
Ive had the tune(TCU and stage 1 ECU ) for over a year with no issues. Just last couple of weeks when dropping from 2nd into 1st gear or reverse to 1st gear and whether its D1 S1 or if i use manual it all does the same thing.
It sort of bounces from 500rpm tp 1200 almost like someone is momentarily hitting the gas pedal and then letting off. It does about 5 cycles of this and then resumes a normal idle

Try this calibration in this exact order, Make sure your transmission is 49-50 c when you start doing this.

Main Pressure Valve Calibration 2294
Clutch Valve Calibration 2295
Clutch Engagement Point Adaptation 2298
Distance Sensor Calibration

[rickr71]

Would you recommend erasing previous calibration? It’s what was originally recommended for the first adaptation I did.
-Erase counter for start and stop processes-
And then do yours:
Main Pressure Valve Calibration 2294
Clutch Valve Calibration 2295
Clutch Engagement Point Adaptation 2298
Distance Sensor Calibration

[joserod92]

Would you recommend erasing previous calibration? It’s what was originally recommended for the first adaptation I did.
-Erase counter for start and stop processes-
And then do yours:
Main Pressure Valve Calibration 2294
Clutch Valve Calibration 2295
Clutch Engagement Point Adaptation 2298
Distance Sensor Calibration

You could do that too. Let us know if this solves your issue, and remember to do it at the exact temperature, also doors shut and foot on the brake. also car must be on.

[rickr71]

The Adaptation/calibration that you recommended worked, so thanks!
Here is the sequence and calibrations performed:

Brought trans to 55c
Key on not running/ ran 3012 Erase counter for start and stop process
Turn car on/ ran 2294 Main Pressure Valve Calibration
Turned car off/waited 30 sec.
Reloaded VCDS/ Turn car on/ ran 2295 Clutch Valve Calibration
Turned car off/waited 15min for trans to go back to under 60c. Getting it back down to 55 is best because if you hit 60 it will say temp is too high.
Key on not running/ ran 3789 Reset start point adaptation
Turned car on /ran 2298 Clutch Engagement Point Adaptation
Turned car off/waited 15min for trans to go back to under 60c.
Reloaded VCDS/Turned car on/ ran 2296 Distance sensor calibration.
Now I need to drive it around while the adaptation engagement point is in learning mode.

It drops from 2nd into 1st with barely even a movement of the RPM needle. Perfect.
Im guessing that it was the 2294 "Main pressure valve calibration" that was the difference. Do you have any insight as to what the fix actually was?

[joserod92]

The Adaptation/calibration that you recommended worked, so thanks!
Here is the sequence and calibrations performed:

Brought trans to 55c
Key on not running/ ran 3012 Erase counter for start and stop process
Turn car on/ ran 2294 Main Pressure Valve Calibration
Turned car off/waited 30 sec.
Reloaded VCDS/ Turn car on/ ran 2295 Clutch Valve Calibration
Turned car off/waited 15min for trans to go back to under 60c. Getting it back down to 55 is best because if you hit 60 it will say temp is too high.
Key on not running/ ran 3789 Reset start point adaptation
Turned car on /ran 2298 Clutch Engagement Point Adaptation
Turned car off/waited 15min for trans to go back to under 60c.
Reloaded VCDS/Turned car on/ ran 2296 Distance sensor calibration.
Now I need to drive it around while the adaptation engagement point is in learning mode.

It drops from 2nd into 1st with barely even a movement of the RPM needle. Perfect.
Im guessing that it was the 2294 "Main pressure valve calibration" that was the difference. Do you have any insight as to what the fix actually was?

I think your guess is as good as mine lol, but im really glad I could help.

[qcrazy]

Did you do the main valve calibration since you installed the TCU tune?

That should always be done after a new TCU tune is flashed. The pressures change a lot with the TCU tune. I suspect the valve calibration took a while to complete? If so, that would be because your valve was operating based on the old pressures, ultimately operating in the complete wrong spot.

I was having a similar issue on my S6 a few weeks ago. I tried to re-adapt and it didnt do anything. I then switched to an IE TCU tune and re-adapted again and that fixed it. My main valve adaption took a long time to finish on the time it worked.

I took some screenshots to make a post about doing a proper adaptation, I just haven't had time to post it yet. Glad you got it figured out!

[DTHS7AR]

I might be a little late but do you have an intermittent start problem also? I had a similar issue on my S6 and it ended up being my HPFPs.

The transmission seemed like it was lurching as you described and would sometimes even throw a malfunction code when I would come to a stop. Turns out fuel was leaking past the worn HPFP pistons and was flooding the pistons, the ECU would compensate and the idle would be all over the place for a couple seconds before it settled down. Also has trouble starting after sitting for 1-2 hours unless I gave it some throttle because of the rich condition.

Originally I thought it was a clutch/transmission issue as well but luckily it ended up being much simpler, maybe worth a check.


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[rickr71]

The 2294 Main Pressure Valve Calibration followed by the other adaptations stopped it from the aggressive lunging.
Honestly the rpm still does "bob" a little bit when i come to a stop occasionally, but it doesn't lunge with the same force as it once did.
Ill keep an eye on it and your suggestion in mind