# Help - S-tronic diagnosis



## Sophus (Apr 26, 2013)

Hi, 
I have a 2.0 TT, built late 2007. In relation to selling it, the car was tested at a generic testing facility, looking for corrosion and all sort of things. The guy doing the testing remarked that he felt the transmission was a bit "jumpy", but his description was very vague. Personally, I have never noticed anything out of the ordinary and drive the car, as well as an A6 with 7 speed stronic every day. Though the 2014 7 speed stronic is a bit smoother than my TT.

The car went in for long life service a few days later and I asked the Audi dealer to specifically look over and test the transmission, based on the remark from the guy doing a test drive the week before. 
The dealer did some test driving and reported that there was a "vibration" they thought originated from the transmission. Very vague. Only vibration I ever felt was from unbalanced wheels, which I had asked to have rebalanced while at service. 
Edit: the dealer found no fault codes. Nothing on diagnosis, but believe that there is something still.

The dealer recommended a "reset" of the stronic to the tune of 250 Gbp. I said ok. Some days later I was called up again and told it did not help with the problem. They said I should return the car for further diagnosis in March, when they would have more time.

I picked up the car Saturday, but none of the guys working on the car were available.

I read up on a lot of posts and info on mechatronic failures etc. Today I have tried all sorts of tests, cold and hot. That includes going 1-2 and vice versa, starting from standstill going both forward and in reverse on a sharp incline etc. 
The results: no clunking, no strange shifts, no stalling and certainly no "vibration".

The only thing worth mentioning is the following, which I would like your opinion on:
When starting from standstill, car in drive or sports, releasing the brake, the clutch engages softly and the car starts to crawl forward, however, it seems the clutch uses about 0.6 seconds before it is fully engaged and full torque reaches the wheels. If I press the accelerator carefully, the takeoff is smooth. The rpm stays at about 1300-1500 until the clutch is fully engaged, whereafter it starts accelerating and rpm increases. In the process, the rpm never dips, and certainly not below idle. No stalling tendency etc.

However, if I am impatient from a standstill and press the accelerator a bit harder after releasing the brake, the clutch engages as described above, first a crawl with clutch partly engaged but as the clutch is fully engaged I get one small but noticeable surge (jump) before the car continues to accelerate quickly but smoothly (or also wheel spin if I pressed the accelerator even harder from standstill).

One might describe it as a brief hesitation while the clutch goes from partly engaged still holding the low rpm until it a bit abruptly is fully engaged with a small jump, whereafter it allows the rpm to increase in accordance with the depression of the accelerator.

So, Is this normal or not?

I always thought it was normal and I would certainly get the same with a manual if I were to press the accelerator impatiently and release the clutch quite quickly at the end of the release cycle, which is essentially close to what I do when impatiently taking off from a standstill with stronic as described above.

I am keen on your opinions as I wonder if the dealer suffer from a potentially costly confirmation bias or the above is abnormal.


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## moro anis (May 27, 2010)

Well, I'm no expert but it sounds pretty normal to me. Some of the hesitation for the impatient take-off could be the turbo spooling up.
Did you pay the £200?


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## Sophus (Apr 26, 2013)

moro anis said:


> Well, I'm no expert but it sounds pretty normal to me. Some of the hesitation for the impatient take-off could be the turbo spooling up.
> Did you pay the £200?


Not yet. The 200 is ex vat. Will discuss the bill with the dealer tomorrow, hence why I am keen to have your opinions


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## 35mphspeedlimit (Sep 25, 2010)

So have they run a report yet and has it thrown any fault codes?? I forget the dreaded list now but my personal fault code was G182 and no software upgrades or gearbox oil changes could help!


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## Sophus (Apr 26, 2013)

35mphspeedlimit said:


> So have they run a report yet and has it thrown any fault codes?? I forget the dreaded list now but my personal fault code was G182 and no software upgrades or gearbox oil changes could help!


Yes. They confirmed that there were no fault codes. Only their "feel".


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## 35mphspeedlimit (Sep 25, 2010)

Sophus said:


> 35mphspeedlimit said:
> 
> 
> > So have they run a report yet and has it thrown any fault codes?? I forget the dreaded list now but my personal fault code was G182 and no software upgrades or gearbox oil changes could help!
> ...


Excellent news!


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## Sophus (Apr 26, 2013)

So, S-tronic owners, comparing your experiences to my description, do you think my transmission is acting normal or not?


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## Algsnowden (Oct 12, 2011)

Sophus said:


> So, S-tronic owners, compared to my description, do you think my transmission is acting normal or not?


I notice the same thing (a forward jerk like you describe) if I apply too much throttle after taking foot off the brakes from standstill. It's even worse when I do the same after placing it in D from neutral.


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## igotone (Mar 10, 2010)

I don't think you have much to worry about quite honestly.


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## powerplay (Feb 8, 2008)

Sounds normal to me.


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## drrawle (Aug 14, 2011)

Sophus said:


> So, S-tronic owners, comparing your experiences to my description, do you think my transmission is acting normal or not?


Sounds normal to me as well.


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## Hurstyv6 (Dec 19, 2013)

My v6 stronic does exactly the same buddy. Sounds fine to me, and reassuring that others do the same thing!


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## RogerB (Dec 16, 2012)

Concur .... all sounds normal.


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## Sophus (Apr 26, 2013)

Thanks guys, you have been most helpful and reassuring.

I had a polite conversation with the service manager at the dealer today and asked him to describe exactly what he thought was the problem. The "vibration" was of course the small jerk when impatiently starting from a complete standstill, just as I assumed, since I after doing all sort of tests could find nothing else worth noticing. He also confirmed that nothing had showed up on diagnosis.

Furthermore, it turned out that the alleged S-tronic specialist that I last week was given the impression had checked my car had in fact not seen my car ever. He had been consulted over the phone by the mechanic and had not given any diagnosis at all. The only one to have tested the car seem to be an ordinary mechanic.

I informed the dealer that I saw the observed behavior as normal. He did not contest this. He voluntarily proposed that I should not pay for the diagnosis or the two reset procedures of the S-tronic. However, he would not admit that there is no problem and probably never were, as he could not exclude anything, which under the circumstances was as much as I had expected to get from him. He added that he saw no reason for me to spend any more money or pursuing this question further, including his previous suggestion to return the car for further diagnosis. I take that to be a de facto admission that he believes that there is no problem. I suspect that the mechanic suffered from a strong case of "confirmation bias" induced by myself as I asked them to check for problems on the basis of the tester's notion that something maybe was not 100% right. So, this misery may be my own doing after all.

I am under the circumstances relatively happy, but annoyed with all the frustration this has caused me.

Again, thank you for your help.


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## igotone (Mar 10, 2010)

Stop worrying about it. If anything goes awry with an s-tronic unit it's usually all too obvious.


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## Sophus (Apr 26, 2013)

No longer that worried. In addition to your reassurances, I found a number of articles and reviews of DSG/Stronic gearboxes, all pointing to the characteristics with DSG from standstill, such as this:

http://www.myturbodiesel.com/wiki/vw-ds ... ronic-faq/

"While some DSG have a small delay in clutch engagement and power delivery from a full stop, this is considered normal and can be expected and compensated for by the driver."


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## Sophus (Apr 26, 2013)

For sake of completeness and to possibly help fellow TT DSG owners with similar symptoms, I thought I should share what I found out regarding my two niggles with the S Tronic. First of all, nothing was wrong with the S Tronic, just as I thought and as you guys said.

Problem 1, occasional hestiation when taking off from standstill:
The delays I saw were not "normal" after all. The problem turned out to be the brake light sensor on the master cylinder. It senses the position of the piston in the master cylinder. If it believes that the brakes are still on, the electronic brain somewhere in the car will not allow throttle to increase rpm or the clutch engagement cycle to continue, in order to protect the transmission and clutch.

It goes like this: You release the brake, hit the accelerator and... nothing but a slow creep for some parts of a second (I have read about guys who have had up to a couple of seconds delay). Then, as the sensor finally understands that the brakes are actually off, clutch engagement continues and off you go, a bit abruptly. However, most people get impatient or stressed by the delay, so they hit the accelerator harder during the pause, leading to an embarrassing take off, wheels spinning and all when the clutch finally engages. Not funny when in traffic. 
Replacement sensor repair kit is about 30 GBP and takes 3 min to replace. The new part looked slightly different from my original part and is probably an improved version. Perfect since! I suspect many other fellow DSG owners have this issue in various degrees without knowing that it is (a) not supposed to be like that and (b) can easily be fixed.

Problem 2, slight, but noticeable vibration when pulling away in 1st:
Actually, I had not noticed it myself as something out of the ordinary, but a guy looking to buy the car pointed it out. The culprit is probably a slightly worn dual mass flywheel. Getting it replaced this week for good measure, though I was ensured that it was not yet "bad enough" to warrant replacement. 
The DMF is designed to absorb vibrations and smooth out the torque. Seems the springs inside these DMFs get worn over time, leading to increase in vibrations being transmitted to the driveline and when really bad, a noise like pebbles in a tin can as the two flywheels begin to rattle. Not a good engineering concept but nevertheless DMFs are found in most modern cars unfortunately.

On a final note, I have to say that I am not very impressed by the first Audi dealer who admitted he found nothing wrong with the S Tronic, though he was sure it had to be "something" and at one point suggested to continue their diagnosing by first replacing the mechatronic to "see if it helped". And of course, he wanted me to foot the bill. The fix turned out to be a 30 quid sensor and a not uncommon fault judging from various VW forums! Stealer!

I wonder how many who have paid for a mechatronic they don't need? I am glad I am not one of them, no thanks to the dealer!


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## igotone (Mar 10, 2010)

Good write up on the issue and I'm glad you got it sorted out.


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## Sophus (Apr 26, 2013)

Update:
I have now driven the car for a month and can confirm that the hesitation upon take off from standstill is definitely completely gone!

Without noticing too much I had subconsciously adapted my driving style to reduce the effects of the fault, but it still annoyed me when it happened, especially in stressful situations, trying to enter at roundabouts etc. It is really nice not having to think about it, just drive and the car does its thing without delay.

Changing the brake light sensor switch is cheap and a 3 minutes job. I suspect quite a few others have the same problem in various degrees, having read all the reviews of cars with dsg mentioning the annoying lack of responsiveness when taking off.


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## properjp (Feb 7, 2014)

Sophus said:


> Update:
> I have now driven the car for a month and can confirm that the hesitation upon take off from standstill is definitely completely gone!
> 
> Without noticing too much I had subconsciously adapted my driving style to reduce the effects of the fault, but it still annoyed me when it happened, especially in stressful situations, trying to enter at roundabouts etc. It is really nice not having to think about it, just drive and the car does its thing without delay.
> ...


Do you have a part no. For said switch mate?


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## Sophus (Apr 26, 2013)

Not at hand unfortunately. When replacing, I noticed that the part number on the new switch was the same as the old one, though they looked different. I got my new one from the dealer. Not too expensive so no real need to shop around to save a few quid.

For sake of completeness of the thread, I should say that fixing the DMF was probably waste of money. Some noises went away, but no real difference in the "vibrations" mostly placebo I think.

What fixed it completely in the end was a throttle body alignment, for free, with my own copy of VCDS. The vibrations at low rpm was simply rough running and slight misfires. A cheap and easy fix that the audi dealer did not diagnose correctly. It was probably them who had disconnected the battery, in the first place and did not do the reset which they should have done according to the repair manual. Idiots.


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## properjp (Feb 7, 2014)

Sophus said:


> Not at hand unfortunately. When replacing, I noticed that the part number on the new switch was the same as the old one, though they looked different. I got my new one from the dealer. Not too expensive so no real need to shop around to save a few quid.
> 
> For sake of completeness of the thread, I should say that fixing the DMF was probably waste of money. Some noises went away, but no real difference in the "vibrations" mostly placebo I think.
> 
> What fixed it completely in the end was a throttle body alignment, for free, with my own copy of VCDS. The vibrations at low rpm was simply rough running and slight misfires. A cheap and easy fix that the audi dealer did not diagnose correctly. It was probably them who had disconnected the battery, in the first place and did not do the reset which they should have done according to the repair manual. Idiots.


I have VCDS mate how can I perform the TB alignment?


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## Sophus (Apr 26, 2013)

It is all in the rosstech wiki, full written procedure. Google will find it for you.

The brake switch replacement fixed the hesitation when starting from a standstill, this was the major issue. 
The Throttle Body Alignment fixed the small "vibrations", which turned out to be rough running due to throttle body being out of alignment/calibration. The latter may happen if battery have been disconnected or power/voltage have run really low, or throttle body have been removed or cleaned. Always do a realignment after those situations.


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## properjp (Feb 7, 2014)

Ordered the brake light switch today, for anyone interested the part no. is...

Part Number : 8P0 698 459 B


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## RogerB (Dec 16, 2012)

Excellent piece of astute observation Sophus and certainly one to remember when and if the "dreaded" mechatronic unit is in the firing line.
Clearly the brake light sensor with the added misalignment problems on the throttle body seemed to add up to a red herring, namely " is it judder and vibration caused by the mechatronic unit".
In your case ... no, good stuff.
Pity more Audi techs don't have similar foresight.


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## mrleow (Apr 3, 2014)

Sophus said:


> Update:
> Changing the brake light sensor switch is cheap and a 3 minutes job. I suspect quite a few others have the same problem in various degrees, having read all the reviews of cars with dsg mentioning the annoying lack of responsiveness when taking off.


Hi.

How do you get to the brake light switch? I fiddle with it for 5 hours and still could not get to the switch.

Pardon the shaky picture.



I guess is yours a Left Hand Drive car with the brake master cylinder behind the air box?


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## mrleow (Apr 3, 2014)

Alright.. Got the answer from another thread. For RHD the whole brake master cylinder has to come off.

:?


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## California3.2Quattro (Nov 27, 2014)

Great thread.

My 2008 TT 3.2 S-Tron does take off a bit less smoothly than my wife's 2012 2.0 S-Tron.

It never felt major to me and always chalked it up to the bigger engine laying down more power. May still indeed be this, and nothing wrong at all.

But for $30, it would be worth it to swap out the switch.

Couple of questions on that:

Looks like part 8P0 698 459 B folks are turning to as the replacement in this thread has actually been superseded to part 5G0698459. I hope the newest part offers the same fix. No reason to believe it has not. See here for the supersede: http://www.ecstuning.com/ES457200/

And, does anyone have help on how to do the swap in a right handed, USA vehicle?

Much appreciated.


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## Ttyson (Jan 1, 2015)

My Tfsi is the same on takeoff sometimes, so just normal.
I've had the mechatronic woes (sorted and it's nothing like you have) so nowt to worry about - rag it!


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## Chubbster (May 18, 2016)

Newbie to TT forum and 3.2 TT. S-Tronic. Does anyone know if the sensor that you changed can be fitted to a Mk1 which is what I have. Only 24k miles from new and its 12 years old. FSH from Audi. I have this lag and it's a pain in the butt. Can't do a swift getaway out of junctions and it did it at T lights. Guy behind thought I had stalled I think, then it took off like a scalded cat!! Not good. Going to try it in manual mode
It's going on a dyno next week but guy says DSG on old models not reprogrammable. Results in a week or so.


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## brittan (May 18, 2007)

The sensor mentioned is the brake light switch. On the Mk2 it's a Hall effect sensor fitted directly to the master cylinder and will not fit a MK1.
The Mk1 has the brake light switch fitted to a bracket above the brake pedal.


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## Chubbster (May 18, 2016)

35mphspeedlimit said:


> Sophus said:
> 
> 
> > 35mphspeedlimit said:
> ...


Probably your wallet is what they want to "feel". Sounds like going to Kwik Fit for a new tyre and being told all your discs and pads are worn and need replacing!!! (When of course they don't!)


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## Chubbster (May 18, 2016)

brittan said:


> The sensor mentioned is the brake light switch. On the Mk2 it's a Hall effect sensor fitted directly to the master cylinder and will not fit a MK1.
> The Mk1 has the brake light switch fitted to a bracket above the brake pedal.


 Thanks for info. Have sent for a manual so will check out oil level etc as sorry but I don't trust any Dealers. I'm an engineer by trade and manage to fix most things without too much trouble. I will continue to work through all the clues as I get to know the car more.


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