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

[Radiation Joe]

Originally Posted by swamp2

In some ways it sounds like you guys have the same software but in other ways it sounds like you don't. It is pretty disappointing that it is not yet totally fixed and BMW are right back to their "it's normal" BS. Strange.

It's different from before. Certainly better, but different. I drove it around for about an hour this afternoon cruising slow through some coastal towns on north Lake Ontario. It still lags, and sometimes significant, but I would say the lag is at worst 30% of what it used to be, and nowhere near as abrupt.

What has me worried is footie's comment about the lag coming back after a time. It could be that the transmission "learns" to lag. Only time will tell. So far I am happy enough with the improvement to stop cussing BMW.

[mikewads]

My DTC equipped M3 should be here at the end of the month. It's currently being transported to the US and will arrive on April 15th. I will let you guys know how the new car does concerning the lag. I drove another 2009 DTC on the my dealers lot which had the lag, so I'm already aware of how to reproduce the lag consistently.

If the lag is present I will be file a complaint with the NHTSA once I can confirm its existence.

[swamp2]

Originally Posted by Radiation Joe

It's different from before. Certainly better, but different. I drove it around for about an hour this afternoon cruising slow through some coastal towns on north Lake Ontario. It still lags, and sometimes significant, but I would say the lag is at worst 30% of what it used to be, and nowhere near as abrupt.

What has me worried is footie's comment about the lag coming back after a time. It could be that the transmission "learns" to lag. Only time will tell. So far I am happy enough with the improvement to stop cussing BMW.

Thanks for clarifying. 30% of what is there now is a huge reduction. Did you also notice that the lag is worse when the car is cold, say first thing in the morning? Has that changed at all? I hope to try this software soon.

Foot has mentioned this learning thing quite a few times and in different contexts. I have never noticed a single bit of long term learning nor adaptation by this unit. I firmly believe it does not do so. The only way it is adaptive from my experience is when you really hit the throttle quick and close to the floor in D modes then follow that with some steady and lower throttle the tranny will hold the recently acquired lower gear much longer than if just prior you had been driving very conservatively. I would call this short term adaptation. I think foot either missed the lag by not enough time driving, wishful thinking or poor observation. I'd be willing to bet that the lag in his car was identical now as to just after his last software update. I know he will guarantee it wasn't. I guess you can decide what makes sense, one of the above, or a very clever long term and driver adaptive software system. Hell they can't get it 100% right without that, how bad would it be if the thing adapted in this quite complex fashion?

IIWY, I absolutely would not worry about the unit performing worse and having more lag slowly over time.

[Radiation Joe]

I'll withhold judgment on the accuracy of footie's observations. I do believe the transmission is adaptive. With 10 or 11 selectable programs, I don't think it's necessary, though. Like I said earlier, time will tell.

[swamp2]

Originally Posted by Radiation Joe

I do believe the transmission is adaptive.

Getting OT but interesting. To clarify, you think the tranny is long term and or individually driver adaptive or short term adaptive as I described above? In what specific ways do you think it adapts? Do you have an example? I could be wrong here so I am certainly open to hearing evidence for opinions.

[gr8000]

Originally Posted by swamp2

The only way it is adaptive from my experience is when you really hit the throttle quick and close to the floor in D modes then follow that with some steady and lower throttle the tranny will hold the recently acquired lower gear much longer than if just prior you had been driving very conservatively. I would call this short term adaptation.

I am of the exact same opinion here on the adaptation issue

[SenorFunkyPants]

While it may have some short term adaptive routines it doesn't seem to exhibit the same sort of long term adaption that plagued the SMG E46 M3s causing problems with clutch wear and flywheel hotspots due to slurred shifts.

[footie]

Originally Posted by swamp2

I think foot either missed the lag by not enough time driving, wishful thinking or poor observation. I'd be willing to bet that the lag in his car was identical now as to just after his last software update. I know he will guarantee it wasn't. I guess you can decide what makes sense, one of the above, or a very clever long term and driver adaptive software system. Hell they can't get it 100% right without that, how bad would it be if the thing adapted in this quite complex fashion?

IIWY, I absolutely would not worry about the unit performing worse and having more lag slowly over time.

I have been driving for over 25 years and a quite skilled observer of driving patterns and car behaviour and I can 100% guarantee that when I lifted the car after the last update there was near enough zero lag and like Radiation Joe has said my car seemed to pick a higher gear i.e. 3rd instead the 2nd gear that is previously did and reverted back to after about 2 or so weeks later. Re-read my original statements about this early experiences and you will see the same pattern as Radiation Joe is now experiencing.

For those first 10 days I exclusively drove the car in auto mode, relishing in this new found pleasure of a gearbox working perfectly and constantly trying to reproduce the lag without success but after this I return to including manual mode and shifting for myself the odd time and it was ever this that the lag and constantly picking 2nd gear started to return and has been there ever since.

Is the gearbox adapting to driving style?

Well given the fact that when driving exclusively in D mode after the upgrade and zero lag to then start using S mode and lag reappeared shortly afterward. Make up your own opinion.

[Radiation Joe]

Lag is more noticeable today.

[swamp2]

Originally Posted by footie

Is the gearbox adapting to driving style?

Well given the fact that when driving exclusively in D mode after the upgrade and zero lag to then start using S mode and lag reappeared shortly afterward. Make up your own opinion.

Again, I would ask, does this already very complex system either update stored parameters based on gathering and analyzing driving style and usage - or perhaps even more complicated - rewrite it's own software again based on similar data capture? I just do not buy it. BMW has never said a word about the system being long term adaptive. I have never noticed a bit of long term adaptive behavior myself, in any mode and with either software revision. Can you (or RJ) tell us one other way in which the transmission software is long term adaptive? Please share.

You can either accept the logical conclusion that you missed something, were too optimistic or that the transmission has code impossibly more complex than we already know it to be. There is not all that much middle ground.

You in particular seem to ignore and reject Occam's razor every chance you get. I just don't get it.

[nitramsen]

To those who believe in the adaptation ability of the software, I think that a lot of the adaptation is in our minds because I have felt the adaption to, especially when I have tried to force the lag.
There have been times where I had to replicate the issue in traffic but could not simply because I tried too hard. Then two minutes late when I was not trying to get the lag it hit me with forward leaping and everything.

This time when I got my car back from the update I drove not try to provoked the lag and it hit me in the second roundabout, then I tried forcing it and it did not appear in the next 10 roundabouts.

Why? probably because I adjusted not the software and probably because BMW has been forcing the lag and trying to solve that.

In my view the new software is better in some ways, but it has only solved a small part of the issue and the dangerous part is still there in my oppinion.

With the new release I am beginning to think that this issue is somehow related to the rear differential being locked and the position of the front wheels.

I have asked this before but I will try again.

Does anyone know if the rear differential has any sensors, actuators etc. or is it pure mechanical without feed back?

This could explain if some does not have the issue, differences in appearance and why most of us say that the lag was not present from the beginning.

Is there anyone claiming not to have the hesitation/lag, especially new cars?

[footie]

Swamp, I can only tell it as I see it and with me my experience was there was very little lag when I drove the car after the update and that instead of trying the shift down into 2nd gear on the corners that I ALWAYS experienced the lag it instead only shifted down to 3rd gear which seemed to cure the lag, or to the point were I found it acceptable.

This continued for about 10 days which was solely driven in D mode and the lag only retuned after I started to use S mode again.

This insistance that we (RJ and myself) missed the lag is a little patronizing. I said that RJ's lag would probably reappear and he is starting to experience it again, thus confirming my fears.

[aus]

Originally Posted by SenorFunkyPants

It does seem like a small number of people with the problem...is it inconceivable that its not just a technical problem affecting certain cars?

It's just a small number of people are willing to spend the 5 minutes it takes to fill out the questions.

BMW is VERY aware of this and won't care until the government MAKES them care about it.

[grayshrk]

I would agree with those that say there is no long-term adaptation capabilities inherent with DCT. I would be absolutely amazed if the DCT software developer included the ability to track your driving habits and, over time, adjust various parameters to have DCT respond in some pre-designed fashion. The complexity involved in tracking, calculating, and adjusting is large and the benefit, from my experience, would be very small (assuming there is some long-term adaptation taking place to my driving style - which I have not noticed). Addtionally, why would BMW create a long-term adaptable tranny and not market that capability to the ends of the earth instead of leaving us to conjecture as to whether it is adaptable?

Now as far as limited short-term adaptation goes, I do believe the tranny does adjust to my style for each drive. For example, if the tranny identifies me as downshifting manually versus allowing the system to take over, I've noticed that the tranny will wait longer for me to initiate a downshift before it takes over. This would be a relatively simple programming effort to accomplish versus some kind of long-term adaptation routine.

[swamp2]

Originally Posted by footie

Swamp, I can only tell it as I see it and with me my experience was there was very little lag when I drove the car after the update and that instead of trying the shift down into 2nd gear on the corners that I ALWAYS experienced the lag it instead only shifted down to 3rd gear which seemed to cure the lag, or to the point were I found it acceptable.

This continued for about 10 days which was solely driven in D mode and the lag only retuned after I started to use S mode again.

This insistance that we (RJ and myself) missed the lag is a little patronizing. I said that RJ's lag would probably reappear and he is starting to experience it again, thus confirming my fears.

But "magically" your good fortune lasted ~10 days and RJs only overnight or so. By the way I never questioned RJs powers of observataion. I only asked him to clarify in what way he thought the tranny is long term adaptive. Continue to believe as you like, magic, hocus pocus, adapativity, fatally flawed, whatever you like. Perhaps BMW even wrote the version of the software you have just for you and they wrote it with a virus that gets rid of the lag and then sneaks it back in later on purpose just to anger Audi fans . The simplest explanation is almost always the correct one.

[gr8000]

Originally Posted by nitramsen

Does anyone know if the rear differential has any sensors, actuators etc. or is it pure mechanical without feed back?

I remember reading somewhere that it is purely mechanical

[footie]

Originally Posted by swamp2

But "magically" your good fortune lasted ~10 days and RJs only overnight or so. By the way I never questioned RJs powers of observataion. I only asked him to clarify in what way he thought the tranny is long term adaptive. Continue to believe as you like, magic, hocus pocus, adapativity, fatally flawed, whatever you like. Perhaps BMW even wrote the version of the software you have just for you and they wrote it with a virus that gets rid of the lag and then sneaks it back in later on purpose just to anger Audi fans . The simplest explanation is almost always the correct one.

Swamp, maybe you should be asking the question as to why RJ had little or no lag at all and why it came back. May I give you my take on this, for a start RJ's software startup is in S3 mode which isn't the same as mine so I would bet anything that he inadvertantly drive it at least once in manual mode before the lag returned which is how it was with me too.

I honest don't know why it stayed away for so long but that is how is was for me and you continued patronizing comments don't suit you and only serve the purpose of making me want to rename you from Swamp2 to Doubting Thomas.

I can't recall whether it was Waremark or not but one of the other UK member also said that his DCT took close on 300~400 miles before the lag reappeared so maybe there is a difference between the setups.

[Radiation Joe]

I've been staying out of this little love fest until I get some more miles on the car. My comment on the transmission being adaptive, was pure speculation. I am trying to determine definitively if this is the case. Since the transmission has so many different modes, and I use at least 4 or 5 of them regularly, I will need more time to determine if the transmission adapts. I'll be driving around an urban area all weekend, so I should have some worthwhile comments by Sunday evening.

[satinghostrider]

Originally Posted by dar2008

Agree, speed bumps are a nightmare in auto mode, especially as London is full of them. I tend to switch to the paddles when driving down such streets.

I just came back from London from a holiday and I thought Singapore was worse. Man how'd you guys drive there given the small roads. And man those bus drivers are really race blood.

[footie]

Originally Posted by Radiation Joe

I've been staying out of this little love fest until I get some more miles on the car. My comment on the transmission being adaptive, was pure speculation. I am trying to determine definitively if this is the case. Since the transmission has so many different modes, and I use at least 4 or 5 of them regularly, I will need more time to determine if the transmission adapts. I'll be driving around an urban area all weekend, so I should have some worthwhile comments by Sunday evening.

Please mate, can you confirm if you have used the S mode as yet because based on my experience it was only when I started reusing the manual mode was when shortly after that the lag reappeared.

[Radiation Joe]

Originally Posted by footie

Please mate, can you confirm if you have used the S mode as yet because based on my experience it was only when I started reusing the manual mode was when shortly after that the lag reappeared.

I used manual mode within 5 minutes of driving off. It was S3. Since then I've used S1, S4 and S5.

[Dascamel]

Don't forget, the ECU adapts to different parameters.(After a full software update it is probably fully reset.) It could effect your perception of what the tranny does or needs to do to keep other issues from occuring. Before a hard stop would create a stall situation, now they resolved that issue possibly creating the lag in the process.
When I first picked up the car I would hit the lag very often, after a week it occurs but not very often. It'll probably occur when I need to dodge traffic, so it can be very dangerous. Its even worse if your not expecting it.