DSG tiptronic issues

[rockhopper]

To those of you who have the wonderful DSG gearbox, I have it coupled to a CR140tdi.

On 2 occasions now I have been using the tiptronic function, and changed down for a junction, I think on both occasions that it happened, I then lost drive. the engine would just rev, with no go. I never experienced this with my previous gearbox.

This happened once a few weeks ago when using the tiptronic, and once last week, after the flappy paddle steering wheel was fitted, so I don't think it has anything to do with that.

Anybody else suffered loss of drive in tiptronic?

I rectified it on both occasions by flicking back into D, but it was a little disconcerting, putting your foot down as you enter a roundabout to find you have lost drive.

Mike

[jrw]

Never had that on mine. Did you not get flappy paddles as standard?

Either way it is slightly dangerous and would get the dealer to look at it ASAP!

[rockhopper]

Flappy paddles are NOT standard. Ben at Shark Performance fitted a vRS 3 spoke flappy Paddle steering wheel for me

I will be getting it over to James ASAP.

Mike

[the_raz]

I did notice something similar when changing rapidly from D to R - the R takes some time to engage, but I have never experienced it during driving. Maybe you put the foot down too quickly, and the gearbox won't release the clutch in a moment of self preservation instinct :rofl:

No, but seriously. I can imagine that something like this has happened: The car thinks you will be changing up next, so it has say 4th gear engaged and ready to use just by changing the clutches. Then if you manually switch down to second it has to rearrange the cogs (which takes some milliseconds) to get to second gear, and if you floor it before the cogs are correctly aligned the clutch will not engage the gear, but rev up in neutral.

This is one of the drawbacks with the dual clutch system - as long as the car has guessed your next gear correctly the gear change is a matter of milliseconds, but when it get its wrong it takes longer to get the correct gear going.

[rockhopper]

I did notice something similar when changing rapidly from D to R - the R takes some time to engage, but I have never experienced it during driving. Maybe you put the foot down too quickly, and the gearbox won't release the clutch in a moment of self preservation instinct :rofl:

No, but seriously. I can imagine that something like this has happened: The car thinks you will be changing up next, so it has say 4th gear engaged and ready to use just by changing the clutches. Then if you manually switch down to second it has to rearrange the cogs (which takes some milliseconds) to get to second gear, and if you floor it before the cogs are correctly aligned the clutch will not engage the gear, but rev up in neutral.

This is one of the drawbacks with the dual clutch system - as long as the car has guessed your next gear correctly the gear change is a matter of milliseconds, but when it get its wrong it takes longer to get the correct gear going.

I was sitting there, coasting, revving the engine for what seemed like ages, without any drive, until I flicked the lever across to D from manual.

Mike

[Speedster]

It happened in mine!

I have a 1.2 TSI DSG 7, no paddles.

I actually never use the tiptroninc function.

In my case, 3 or 4 time in the one year of ownership, the car would simply rev after I engaged D from R. Pressing the break and then the gas pedal immediately restores operation.

There are no faults stored in the car computer….

[900000]

This is not happened on mine... either from R to D or when I rarely use Tiptronic.

[Allams Skoda]

Sounds rather odd, can't say I've experienced it ever on a DSG box.

Does the gear indicator flash on the maxi-dot when it has lost drive?

[the_raz]

In my case, no. So I guess it's just too much revs for the clutch to let go. No error, just normal error avoiding from the gearbox. It seems that changing between R and D takes surpisingy long, and if you step on the throttle to soon the car won't be in gear and the clutch will not release.

Rockhopper: did you accelerate immediately after changing down? If so I guess it is possible that the car did not complete the gear change in time, and the revs were too high for the clutch to release.

[eccleshill]

Rockhopper: did you accelerate immediately after changing down? If so I guess it is possible that the car did not complete the gear change in time, and the revs were too high for the clutch to release.

Surely not. Gear changes are so fast (40 miliseconds?) that the clutches aren't open long enough for the unloaded engine revs to rise. It changes up without any need to release the throttle pedal even with it buried in the carpet.

I think there is a fault in the gearbox - sounds like it is finding a false neutral.

Unless!

Could it be you have inadvertently selected neutral? Is it possible to select neutral with the flappy paddles? Pull them both up at the same time or some other combination perhaps.

[900000]

Could it be you have inadvertently selected neutral? Is it possible to select neutral with the flappy paddles? Pull them both up at the same time or some other combination perhaps.

Ah...... yes I have read on other cars something like that does indeed happen when you pull both paddles at the same time.....

[Allams Skoda]

Surely not. Gear changes are so fast (40 miliseconds?) that the clutches aren't open long enough for the unloaded engine revs to rise. It changes up without any need to release the throttle pedal even with it buried in the carpet.

I think there is a fault in the gearbox - sounds like it is finding a false neutral.

Unless!

Could it be you have inadvertently selected neutral? Is it possible to select neutral with the flappy paddles? Pull them both up at the same time or some other combination perhaps.

Pulling both paddles doesn't do anything apart from select whichever ratio you asked it to do first (impossible to pull the paddles at exactly the same time)

Oddly this does work on a friends Ferrari I tried, which is useful for hilarious starts and destroying the clutch. The gearbox on that isn't nearly as good as DSG....

[rockhopper]

From memory I think I was changing up at the time, not down....I was approaching a junction/roundabout in possibly 2nd, it was clear to go, so up to 3rd and off, coasting instead of driven wheels. No dashboard lights or messages.

As James says, I have not noticed anything happen when both are pulled at the same time.

I will keep playing with tiptronic to see if I can replicate the fault. You can't select neutral with the flappy paddles, only via the gearshift. Being a long term DSG owner, I'm aware of going fairly slowly from R to D or D to R.- like the park assist, if you do it too fast, it won't work....

It was like a false neutral, that some motorbikes used to have

Mike

[Allams Skoda]

Would be handy if we can replicate it, but at least get it in the workshop tommorow for a scan and see if there has been a fault recorded somewhere.

When you put it back into D did it go back into drive with a clunk or did it use perhaps the wrong gear to what it would normally use?

[the_raz]

Surely not. Gear changes are so fast (40 miliseconds?) that the clutches aren't open long enough for the unloaded engine revs to rise. It changes up without any need to release the throttle pedal even with it buried in the carpet.

I think there is a fault in the gearbox - sounds like it is finding a false neutral.

Unless!

Could it be you have inadvertently selected neutral? Is it possible to select neutral with the flappy paddles? Pull them both up at the same time or some other combination perhaps.

The changing from one gear to the next (one clutch opens and the other closes) is very quick, but it's not the same thing as selecting the next gear to be activated, and this is where I think you can catch the DSG off guard by manually selecting another gear than the car was planning for. With dual clutches the next gear is already selected at gear change, and the clutches just steer the power to the other axle. (hopefully you understand what I mean)

[roguebrit]

I do use the tiptronic function all the time and have never had the problem you describe - or any, for that matter. i don't have paddles, of course - but almost as a matter of course, when driving fastish stretches with roundabouts - it's flick to the left, tap, tap, down to 4th or 3rd, into the roundabout, flick to the right and away. Sorry you are having a problem - it will be interesting to know what is causing it, indeed.

[rockhopper]

I was out again today and it happened again. changed down to 4th, then 3rd, on the power and.......an engine that revved. after a couple of seconds, the clutch engaged and off I went for the rest of my journey, which was uneventful.

I was driving briskly, but not fast, as the speed limit in the local sussex lanes is often only 40mph

Elsie the Helipad is going in on monday for investigations.

[bahnstormer vrs]

I was out again today and it happened again. changed down to 4th, then 3rd, on the power and.......an engine that revved. after a couple of seconds, the clutch engaged and off I went for the rest of my journey, which was uneventful.

I was driving briskly, but not fast, as the speed limit in the local sussex lanes is often only 40mph

Elsie the Helipad is going in on monday for investigations.

Sorry to hear you are having issues with your DSG.

Is it possibly the case that you are 'getting on the power' just the merest fraction too soon and catching the gearbox in neutral? or are you possible changing down too soon that will make the revs in the lower gear too high and the gearbox goes into 'protection mode'?

Good luck with the diagnostics tomorrow though.

[rockhopper]

Sorry to hear you are having issues with your DSG.

Is it possibly the case that you are 'getting on the power' just the merest fraction too soon and catching the gearbox in neutral? or are you possible changing down too soon that will make the revs in the lower gear too high and the gearbox goes into 'protection mode'?

Good luck with the diagnostics tomorrow though.

I was on the brakes, then change down the box, equivalent to block changing (as per the police method & IAM), so probably 2 clicks on the paddles, then on the power, and then no drive. I was changing down so that the revs would be between 2500 & 3000rpm, giving plenty of room to accelerate before changing gear.

The gearbox will not let you change down too soon. just won't change. Like moving off in first, it won't go into 2nd until you are doing 5-10mph, even if you ask it to change sooner, it will just ignore you! or at 30mph in 5th and you ask it to go into 6th, it just ignores your input.

Elsie is booked in all week I'm being given a Fabia 1.2.

[freedie]

Are you telling us that you are "boxing down" (i.e. changing from say 5th to 3rd, or 4th to 2nd) using a DSG? I ask this because you have mentioned 2 clicks on the paddles.

If the answer is yes, you have managed to do the one thing the DSG was designed to avoid ever needing to be done.

I could also comment on your two authorities; but I will bite my tongue instead Ouch!

[rockhopper]

It is a sequential gearbox, so you go from 5th through 4th to 3rd. 2 clicks on my paddles or 2 back flicks on the gear lever. You are right it can't go direct from 5th to 3rd. Just like I would have done on a motorbike.

[freedie]

Yes; but my poimt is you have to engage the middle gear before you try the one below...

Your 'bike prolly does not have a DSG?

Edited 20 March, 2011 by freedie

[rockhopper]

You don't need to engage as such, for instace at 40mph in 6th, you want to change down to 3rd for a bend, just tap, tap, tap and you are in 3rd.

[freedie]

If you mean your 'bike, I agree. If you mean a Yeti with DSG boxing down 3 is better than boxing down 2; but better than all that is not to box down in the DSG Yeti AT ALL!

Just to make it clear, I am not "having a go". Instead I am trying to point out that if you only experienced the problem randomly, you may not have realised that the problem only occured when you box down rather than reduce speed gear by gear?

Edited 20 March, 2011 by freedie

[hertsnminds]

From the Wikipedia article on the DSG gearbox...

Depending on the vehicle speed, and amount of engine power being requested by the driver (full throttle, or part-throttle normal driving),[4] the DSG then upshifts. During this sequence, the DSG disengages the first outer clutch whilst simultaneously engaging the second inner clutch[2][3][4] (all power from the engine is now going through the second shaft), thus completing the shift sequence. This sequence happens in 8 milliseconds (aided by pre-selection),[3][4] and can happen even with full throttle opening, and as a result, there is virtually no power loss.

For downshifting

Downshifting is similar to upshifting but in reverse order, and is slower, at 600 milliseconds, due to the engine ECU needing to 'blip' the throttle, so that the engine crankshaft speed can match the appropriate gear shaft speed.

For non sequential changes

Under "normal", progressive and linear acceleration and deceleration, the DSG shifts in a "sequential" manner, i.e. under acceleration: 1st > 2nd > 3rd > 4th > 5th > 6th; and the same sequence reversed for deceleration. However, the DSG can also skip the normal sequential method, by 'missing out' adjacent gears, and shift two or more gears.[3] This is most apparent if the car is being driven at sedate speeds in one of the higher gears with a light throttle opening, and the accelerator pedal is then pressed fully to the floor against a further additional 'resistance'; this activates the "kick-down" function. During kick-down, the DSG can skip gears,[10] going from 6th gear straight down to 2nd gear (conditions permitting).

Source http://en.wikipedia.org/wiki/DSG_gearbox