M-DCT Lag issue. Owners please post your car info here

[Phoenix 21st]

Originally Posted by footie

We are all going very close to the situation that I suggested a few weeks/months ago when I said the gearbox software was a learning software. And in this I don't mean holding on to a gear just because you have floored the throttle, I am convinced that the software adapts to the driving style and adjusts to it's changes.

Remember I said that after I got the upgrade done I exclusively drove the car in D-mode for those first two weeks, trying to reproduce the lag but couldn't, yet when I started to introduce the S-mode again and make to shift decisions instead of the gearbox software the lag slowly but surely started to return and within about 4~5 days it was back to normal. Guys I continue to believe that it's a lot more advanced than you think and maybe not for the better because of it.

P.S.

I am really looking forward to the summer and getting to enjoy the M3 to the full. It really is an incredible machine and much better than I ever believed it would be.

i subscribe to similar thoughts about the trans as footie it terms of the 'learning' ability. I am on progman 31.2 (Dec 2008) and after leaving the dealer it was fine, instant up shifts all seemed fine. slowly lag returned but not as bad as when it was brand new. Earlier this year i began to loose down shift upon request. Went into the dealer in March, they said nothing was done and no software update was available to stop the ignored downshift request however after a row with the dealer (me telling them that i would drive the car 2 miles along the road and same would happen) i drove off and magically every request was fine, double shift, fast shifts etc. I can only imagine that they 're zeroed' the software and declined to tell me as then it might imply liability. Since then i have noticed a couple of ignored downshifts and belive it will get worse.

[SenorFunkyPants]

Originally Posted by alito

Coming from the service manager of a large BMW dealer. Take it as you wish. I am going to try it.

The old E46 M3 SMG software was supposed to have a learning element to its software (the SMG was also produced by Getrag as is the DCT) and it could be reset at a BMW dealership as part of the clutch "teach-in" process.
I don't know if the DCT software has a learning process but there appears to be precedent for it and at least one other DCT user (Mitsubishi IIRC) state that its transmission has a driver style learning system.

[Phoenix 21st]

Originally Posted by SenorFunkyPants

The old E46 M3 SMG software was supposed to have a learning element to its software (the SMG was also produced by Getrag as is the DCT) and it could be reset at a BMW dealership as part of the clutch "teach-in" process.
I don't know if the DCT software has a learning process but there appears to be precedent for it and at least one other DCT user (Mitsubishi IIRC) state that its transmission has a driver style learning system.

I remember the Mitsubishi Galant was sold with the gearbox that 'will adapt to your driving style' and that was years ago.

[jml]

My B5 S4 tip adapted, there was even a variable in the ECU that kept track of how aggressive it was shifting. Nothing really smart, but it definitely adapted to your driving style, mainly with downshift and gear holding patterns.

[swamp2]

We need to carefully distinguish between short term and temporary learning/adaptation and long term and permanent learning/adaptation. I have seen nothing in the technical information nor particularly strong evidence in the anecdotes herein that the unit has the long term nor permanent variety. A trade between two memebers both with DCT might be the ultimate easy test. If both agreed that the others transmisson behaved differently that would be fairly strong evidence.

I still say just based on common sense that this is too complex for the cars systems to observe, record and process inputs to determine elements of a drivers "style" and then reprogram or update tables used by the DCT software. It simply is not needed nor required and adds an enormous layer of complexity.

[von_zoom]

I think that a service fix has been issued. You may wish to check on:
vz

SI B28 06 08

Double-clutch Transmission with Drivelogic October 2008

Technical Service

PERFORM THE PROCEDURE OUTLINED IN THIS SERVICE INFORMATION ON ALL AFFECTED VEHICLES PRIOR TO CUSTOMER DELIVERY OR THE NEXT TIME THEY ARE IN THE SHOP FOR MAINTENANCE OR REPAIRS.


SUBJECT
Service Action: M3 with M DCT – Reprogramming for Incorrect DCT Clutch Operation


MODEL
E90, E92, E93 M3 with S65 and M DCT transmission produced up to 09/10/08


SITUATION
Due to the M DCT software error, the customer may experience a sudden loss of engine power when decelerating to a complete stop with light brake application, or when performing a multistage downshift (e.g. from 5th to 2nd gear, or from 6th to 3rd gear). At the same time, the transmission will shift into neutral, and reduced power steering assist will be detected.

In order to correct this situation, BMW is conducting a Service Action to reprogram the M DCT transmission control module on all affected vehicles. With the completion of this Service Action, the software of the complete vehicle will be updated as described in SI B09 05 01 (Coding, Individualization, Programming), Procedure B.

[Dascamel]

Eh, thats old... we're waiting on the next upgrade, that one fixed a ton issues and created the low speed. Just did a track day though, transmission was perfect. Not much gliding to a close stop helps.

[gr8000]

Originally Posted by von_zoom

I think that a service fix has been issued. You may wish to check on:
vz

SI B28 06 08

Double-clutch Transmission with Drivelogic October 2008

Technical Service

PERFORM THE PROCEDURE OUTLINED IN THIS SERVICE INFORMATION ON ALL AFFECTED VEHICLES PRIOR TO CUSTOMER DELIVERY OR THE NEXT TIME THEY ARE IN THE SHOP FOR MAINTENANCE OR REPAIRS.


SUBJECT
Service Action: M3 with M DCT – Reprogramming for Incorrect DCT Clutch Operation


MODEL
E90, E92, E93 M3 with S65 and M DCT transmission produced up to 09/10/08


SITUATION
Due to the M DCT software error, the customer may experience a sudden loss of engine power when decelerating to a complete stop with light brake application, or when performing a multistage downshift (e.g. from 5th to 2nd gear, or from 6th to 3rd gear). At the same time, the transmission will shift into neutral, and reduced power steering assist will be detected.

In order to correct this situation, BMW is conducting a Service Action to reprogram the M DCT transmission control module on all affected vehicles. With the completion of this Service Action, the software of the complete vehicle will be updated as described in SI B09 05 01 (Coding, Individualization, Programming), Procedure B.

I don't think this is the DCT lag issue. This seems to cover total engine power loss / stall after multiple downshifts.

I thought it was corrected for good in a previous fix? I had a few stalls but after an update this never occured to me.

[GT3 Tim]

Originally Posted by gr8000

Mine has started to reject upshift commands occasionally a month or so ago. I am not sure if this has to do with any sort of adaptation of the DCT-algorithm or whther the upshift paddle has gone bad. I will continue my observations...

Mine ignored downshifts and upshifts. ALSO, it would skip a gear too (eg: 5th to 3rd).

My downshifting was much worse than the up shift. I could get it to skip a gear downshifting or ignore the command altogether a lot. The upshifting problem would happen only once in a while. I had my dealer order new paddles for me. They had the downshift paddle assembly and installed that. I am still waiting for the upshift paddle.

I have had the car back several weeks and it has not ignored or skipped a downshift since. Maybe you should ask for some new paddles!

[mkoesel]

Originally Posted by swamp2

And you did not get any recent software updates correct?

That's right swamp - no updates since the last "fix" that ended up causing (or at least exacerbating) the now famous lag issue.

Perhaps some will think this is a semantic argument, but it really is not. Perhaps the explanation is that the transmission behaves differently when driven differently. Well that is obvious, it does. But the question is why do you ascribe some long term adaptation to the trans when it is you that has changed?

Well, like I said in my post, I am not necessarily saying that I think the car does have long term adaptation. But something is different now. Over the past couple days I've noticed that the rejected downshifts are happening in some other instances too. However, I've also noticed that I can sometimes get the shift to execute after it was rejected a couple times by holding the paddle longer. This could be a sign that the paddle itself is just going bad, or the switch is wearing. I have had experience in the past with the switchgear in my BMWs becoming less responsive over time so this is not so hard to believe. And it could be that the reason it seems to happen when the car is not warmed up is that it takes me a few tries to remember to be more deliberate with the paddle pulls.

As for the clunking, I think that might indeed be my driving style. I've noticed that a few times I have been actually letting my foot off the accelerator just after shifting. This is of course not planned - it is due to traffic moving into my path without warming (such as people changing lanes without signaling). Normally, in low traffic situations, I would keep my foot in it, or if slowing down I would lift my foot a bit before the shift, not after. So the clunk does make some sense here, it is driveline "whiplash" if you will.

Here is the big question. If your driving style reverted back to your old style would the transmission also "revert" back. My point of view on this is again that the unit has no capability for long term/driver specific adaptation.

I understand your points, and I do agree that the long-term adaptation issue is still probably more unlikely than it is likely. However, we know the BMW Steptronic has this capability. The big difference though is that BMW specifically advertises it in that case. I too find it hard to believe they would not also adverstise this feature of the DCT/M-DCT transmission if it existed.

[gr8000]

Originally Posted by GT3 Tim

Mine ignored downshifts and upshifts. ALSO, it would skip a gear too (eg: 5th to 3rd).

My downshifting was much worse than the up shift. I could get it to skip a gear downshifting or ignore the command altogether a lot. The upshifting problem would happen only once in a while. I had my dealer order new paddles for me. They had the downshift paddle assembly and installed that. I am still waiting for the upshift paddle.

I have had the car back several weeks and it has not ignored or skipped a downshift since. Maybe you should ask for some new paddles!

Thanks for your feedback. The problem is I cannot reporduce this in front of the dealer so it will be a strugle to ask them to change the paddles becasue of this.

BTW, yesyerday I had another missed upshift and I hit the rev limiter hard in 1st... Maybe they can read that and be convinced (although again this does not suggect the paddle is faulty - they may say I was sleeping). Maybe the system has produced some error code for the mulfunctioning upshift paddle...

If this thing continues I will take it to the dealer (to also check if there is a new DCT update BTW!)

[alito]

no news?

[GT3 Tim]

Originally Posted by gr8000

Thanks for your feedback. The problem is I cannot reporduce this in front of the dealer so it will be a strugle to ask them to change the paddles becasue of this.

BTW, yesyerday I had another missed upshift and I hit the rev limiter hard in 1st... Maybe they can read that and be convinced (although again this does not suggect the paddle is faulty - they may say I was sleeping). Maybe the system has produced some error code for the mulfunctioning upshift paddle...

If this thing continues I will take it to the dealer (to also check if there is a new DCT update BTW!)

Keep taking it back if the problem continues. When I did the test drive with the dealer, it would not do it. I got it to skip gears and ignore commands roughly 10 times on the way to the dealer that morning!!! I just told the shop foreman to go out and drive it...I don't know if he did or took my word for it. However, after having the downshift paddle replaced, it hasn't missed a beat! I had the upshift paddle screw up a couple of times (like 2 or 3), but have not seen it in a while. They ordered that paddle for me.

[jeff4598]

Only have my car 4 days and 82 miles but I have watched and in D4 the downshift to first gear occurs at 4 or 5 mph- people have said it happened at 1-2 mph- is this the way to ensure that rolling stops bring you into first gear and avoid lag? car production finished ~4/3 i believe.

[GT3 Tim]

Originally Posted by jeff4598

Only have my car 4 days and 82 miles but I have watched and in D4 the downshift to first gear occurs at 4 or 5 mph- people have said it happened at 1-2 mph- is this the way to ensure that rolling stops bring you into first gear and avoid lag? car production finished ~4/3 i believe.

Probably! In D mode, mine does not go into first until I am basically STOPPED. If I try to do a rolling stop, it will not go into first. The lag, for me, is really apparent in 2nd gear at low speeds (under 25mph). Slowing for speed bumps, etc. is a total PITA! I have gotten used to switching to S mode when doing this sort of driving...although I don't think I should have to!

[ONE92]

I have also had this problem. I just wanted to show pencil geeks statement after he had his ecu flashed. I think it is quite interesting and has a lot of relevance to this topic, but was posted elsewhere.
PENCIL GEEK
"I've noticed considerably more torque in the bottom end and midrange up to about 5000 RPMs. The extra torque makes the car much more drivable around town, and much easier to punch the gas in any gear to get the acceleration you desire. Before the ECU upgrade, my car seemed like it would bog down quite a bit at lower RPMs. It seemed like my car had it's good days, and it's bad days. Some days it would bog down, and other days it wouldn't. Most likely, this situation is caused by the ECU itself...because the ECU dynamically adapts over time to your driving style -- delivering performance based on how you've driven in the past. The ESS upgrade doesn't disable the adaptive behavior of the ECU -- but instead changes how it adapts. Instead of bogging down in low RPMs on 'bad days' -- the ESS ECU is always-on, ready to deliver maximum torque. In my opinion, the extra torque is very nice -- something I wished the stock motor had."

[riyatch]

Ive just purchased an 09 e90 MDCT with a 11/25/08 build date and was wondering what software I should have? My car is to be delivered tommorrow and I'm a little nervous after reading all the threads on lag/stalls. My wife will occasionally need to drive the M with our two kids, 3 and 1 yr olds, and I would hate for them to be in danger from a lagging and stalling transmission. She will be using it in D mode exclusively.

[GT3 Tim]

Originally Posted by ONE92

I have also had this problem. I just wanted to show pencil geeks statement after he had his ecu flashed. I think it is quite interesting and has a lot of relevance to this topic, but was posted elsewhere.
PENCIL GEEK
"I've noticed considerably more torque in the bottom end and midrange up to about 5000 RPMs. The extra torque makes the car much more drivable around town, and much easier to punch the gas in any gear to get the acceleration you desire. Before the ECU upgrade, my car seemed like it would bog down quite a bit at lower RPMs. It seemed like my car had it's good days, and it's bad days. Some days it would bog down, and other days it wouldn't. Most likely, this situation is caused by the ECU itself...because the ECU dynamically adapts over time to your driving style -- delivering performance based on how you've driven in the past. The ESS upgrade doesn't disable the adaptive behavior of the ECU -- but instead changes how it adapts. Instead of bogging down in low RPMs on 'bad days' -- the ESS ECU is always-on, ready to deliver maximum torque. In my opinion, the extra torque is very nice -- something I wished the stock motor had."

That would be motor related issues. IIRC, the DCT uses a seperate program. I am well aware of adaptation of OBD II programming. I don't think the DCT software is related to this. I have not seen a difference in my cars shifting behavior whatsoever.

From my experience with DME's, the adaptation PG refers to is simply for the engine ECU (Engine Control Unit), not the tranny. This has been on all OBD II vehicles since 1996.

[gr8000]

Originally Posted by ONE92

I have also had this problem. I just wanted to show pencil geeks statement after he had his ecu flashed. I think it is quite interesting and has a lot of relevance to this topic, but was posted elsewhere.
PENCIL GEEK
"I've noticed considerably more torque in the bottom end and midrange up to about 5000 RPMs. The extra torque makes the car much more drivable around town, and much easier to punch the gas in any gear to get the acceleration you desire. Before the ECU upgrade, my car seemed like it would bog down quite a bit at lower RPMs. It seemed like my car had it's good days, and it's bad days. Some days it would bog down, and other days it wouldn't. Most likely, this situation is caused by the ECU itself...because the ECU dynamically adapts over time to your driving style -- delivering performance based on how you've driven in the past. The ESS upgrade doesn't disable the adaptive behavior of the ECU -- but instead changes how it adapts. Instead of bogging down in low RPMs on 'bad days' -- the ESS ECU is always-on, ready to deliver maximum torque. In my opinion, the extra torque is very nice -- something I wished the stock motor had."

I was also wondering what this has to do with this thread, namely with the DCT lag which is the main issue or with the side discussion on the possibility of the DCT software (not the ECU) having adaptation properties...

[ONE92]

Originally Posted by gr8000

I was also wondering what this has to do with this thread, namely with the DCT lag which is the main issue or with the side discussion on the possibility of the DCT software (not the ECU) having adaptation properties...

It was related to Footies experience on page 2. Pencil Geek states that the ecu flash makes the car adapt differently to your driving. I should have stated it had to do with Footies exp. after his ecu flash. MY BAD

[SenorFunkyPants]

"A further advantage of this high performance transmission management is that it is able to provide the ideal ratio at all times for maximum efficiency, taking the particular style of motoring preferred by the driver into account."

Does that infer some kind of adaption?

Taken from: BMW Media information on the M double-clutch transmission.

[swamp2]

We all know the transmisson is short term and non user specific adaptive. Peg the throttle and then lift and the car will hold a gear longer before the next auto upshift. This is adaptation, it is good but it is absolutely not long term nor driver dependent.

GT3 Tim: Although the ECU and TCU may be separate software they are closely linked and share a lot of information. One simple proof of that is its ability to cut throttle for a very short time on upshifts and of course to rev match. I continue to claim the this lag is actually DCT related but the throttle is the real culprit not the control of clutches or gears. The lag is the lack of throttle response, NOT a clutch delay.

For those who did not see it ESS claims they will be releasing DCT software that fixes the lag. Link.