DCT transmission lag

[cheshirecat79]

Originally Posted by BatteryPowered

For those of us who come from automatics, we're spoiled by "always-on" action of torque converter and expect the car to start moving the moment the foot is off the brake pedal.
For those of us who come from manual, we're already used to some delay before going while we manually engage clutch.
M DCT is probably more refined and probably has beefier clutch that can take more abuse, so there's no need to baby it as much during take offs. Can't expect M-level of refinement from 1 series BMW.

While there is certainly some difference between gearboxes, the issue being discussed here is most likely errors in the shift logic at the software level, not a hardware limitation.

[Overpar56]

Agree. Software controls everything now days. I find it more responsive in sport mode than non-sport mode. To me, the throttle tip-in is better. I tend to use sport mode around town. It might cost me a bit of fuel, but it drives better.

[jester17]

Originally Posted by houtan

Jester17: you take a print out of the SIB to the dealership?

I must have missed it... can you or someone direct me to the .pdf and/or link?

[houtan]

Go to post 4 of this thread. I recommend reading the thread that is linked in post 4, but you will find a copy of the SIB on page 5.

[JB007]

This thread is one of the reasons I went with a 6 Speed manual gearbox. So simple, never fails, etc... Hoping you get your issue resolved.

[-c-]

After I got the new update to my DCT it engages immediately and have no lag. No roll back either.

Maybe you would need the update. BMW has different programming for problematic cars.
When I worked at Bavarian BMW in Michigan their was code for cars with shifting issues that new
cars that came from the factory didn't have.

Of course that was 10 years ago

MINI was similar.

[shah269]

any news?

[Overpar56]

Originally Posted by Overpar56

I had both the dealer I bought it from and the dealer I have it serviced at pull the history. I guess I need to query them about the DCT SIB, but the three DCTs I drove only one lagged at a dead stop. It was a 2011.

I stand corrected. Today on two different trips I had several lags. It seems common to what others have experienced. Slow roll while in first, nail it, wait for it to move. The engine doesn't rev high then catch but there's a good 1 sec or more lag. It is kind of scary making a turn against traffic when this happens.

Sounds like dealer time for a reflash.

[No Style 135is]

Originally Posted by -c-

After I got the new update to my DCT it engages immediately and have no lag. No roll back either.

Maybe you would need the update. BMW has different programming for problematic cars.
When I worked at Bavarian BMW in Michigan their was code for cars with shifting issues that new
cars that came from the factory didn't have.

Of course that was 10 years ago

MINI was similar.

So if I go to the dealer, can I check the software and update right away?

Sometimes this lag is annoying me!

[Overpar56]

I'm wondering if this would fall under a manf defect and safety hazard? I guess if enough people complain or the NTSB gets involved there might be a recall.

[PopsnBurbles]

My DCT engages P/N -> D/R almost like a normal automatic. An it can also transition from D/R back to P/N as quickly.

When I'm stop and go on an uphill, my car tends to rollback sometimes! On other instances, it remains in place. I'd say it's 50/50 when it does and doesn't roll back.

However, from a stop while in D/M1/M2 and I let go of the brake pedal and step (slightly) on the accelerator. My car lags for half a second and pounces forward as if trying to catch up for the time it's lost. This isn't necessarily cured by engaging sport button with M1/S1...In fact, it's more evident.

Do I need the update?

[hatepotholez]

Originally Posted by Overpar56

I'm wondering if this would fall under a manf defect and safety hazard? I guess if enough people complain or the NTSB gets involved there might be a recall.

Is NHTSA and the NTSB the same? I remember I had a issue with my dads 09 Corolla steering, I notified NHTSA and TOYOTA was adamant about getting it fixed. Toyota did an alignment, new front tires and also checked the software. The car drove much better after that.

[02rsxpilot]

Originally Posted by BatteryPowered

OP, I have similar issue on my 2013 car. It's not 1.5s, but it's not instantaneous like slush box with torque converter. It is pretty annoying and to this day I am struggling to take off without jolts. I figured it's normal for a car (since it shifts ridiculously fast once it's going) and that that's the best BMW could do under circumstances. This is my first dual clutch tranny.

Someone asked about rollback, yes the car rolls back a tiny bit on banked road when you take off. US drivers are so used to automatics, the moment they see my brake lights go off they start rolling, only to see my car roll back at them. I've had a few moments where SUVs would hug my ass and would nearly crash at me during take off.

I also had a "moment" where I was trying to avoid being rear-ended, floored the accelerator only for car to sit there and think for half a second before taking off (it was half a second too late, luckily SUV managed to avoid crashing into me).

Long story short, this is last DCT i am getting for daily driver. It's extremely awesome during hard acceleration and active driving, but not when you have to stop every block for stop sign.

PS.

If I slow down to near-stop (stop sign) and then try to go, car would hunt for gear (my guess 1 or 2 hard decision huh?) for about half a second before finally getting into a gear and going.

Reviving old semi-old thread because if I could cure this one issue, this car would be brilliant on the street. Battery describes the behavior the best. (Note that the OP's description is completely different from the symptoms I believe the rest of us complain about).

The car simply does not react from slow speeds or stops. It does not rev, it does not change gears, it does nothing. The expectation is not that the car begins to roll forward when the foot is off the brake. The expectation is that the car moves when I press the accelerator. The failure of the car to react in this situation happens to me at least half a dozen times per day, and as Battery described, it can be downright dangerous, not just because of the lag in reaction, but because of the sudden lurch after the lag.

The behavior is not driver dependent (my dad and even my wife have noticed it). Driving in D/S, Manual, with or without Sport, and with or without DTC on/off in any form makes absolutely no difference. No software update from the dealer has fixed it either. I have the latest SIB and dealer claims the transmission operates as designed.

As others have noted, this is not a mechanical issue! BMW's M-DCT does not have this problem. This is a programming/software issue. I heard rumors that the software update from the PPK 1 alleviates the issue. Can anyone confirm or deny this? I suppose if a 135is owner still has the same issue, that would answer that question.

[saveferris]

hey 02rsxpilot read through this thread

http://www.1addicts.com/forums/showthread.php?t=1033690

I had the same or similar issue as you and got the update noted in the above thread and car is now night and day different. Zero hesitations, zero lag at all.

I think it's SIB 12 15 14. Your SA should know what to do with that, it describes the same/similar issue that you have and the remedy - software update. I cannot recall what the software version is but I think it's in that thread.

Good luck.

[Overpar56]

Multiple threads on this subject but since SIB 12 15 14 I've had zero issues. I do have PPK1 so in not sure if that makes a difference. I'm very satisfied with the fix. I've tried every which way to make it fail and so far nothing upset the transmission.

[guey]

Originally Posted by shah269

OK here is what you do...use this new thing...i think it's called a clutch and a stick shift....
Just in case you didn't know what it looked like...
http://www.aamcovenice.com/wp-conten...ch-Pedals1.jpg
and
http://timebusinessblog.files.wordpr...320%26crop%3D1

NOT FUNNY People are looking for help.