Rough downshift from 3 to 2 in Auto on a DCT

EBM4 · 08-02-2016, 11:37 PM

Guys I'm getting a thought shift when coming to a stop from 3rd gear to 2nd gear Almost like the rev matching is note quite enough RPM's when the car shift down causing a jerk slowing the car down.

Started after JB4 was installed. I'm running map0 or map2.

Any ideas what the issue could be.

M4BUM · 08-03-2016, 07:15 AM

i have the same problem since day one. problem ist that it doesn't happen everytime.
i have no tune etc. my dealer says that this is normal.

maybe someone else has the same problem or has a solution?

Kr3st · 08-03-2016, 07:31 AM

I have same problem. It's happened since day one. Very annoying. I wonder if the GTS software or TCU flash fixes it.

CaryTheLabelGuy · 08-03-2016, 08:11 AM

Quote:

Originally Posted by Kr3st

I have same problem. It's happened since day one. Very annoying. I wonder if the GTS software or TCU flash fixes it.

The DCT is a little quirky at times, but this is the nature of the beast. Sometimes the computer doesn't calculate the clutch slip-points just right or doesn't perfectly anticipate the drivers inputs.

I'm going to flash my ZCP's DCT to the GTS firmware this week. I'll report back on my findings.

Jerich0 · 08-03-2016, 08:34 AM

Quote:

Originally Posted by CaryTheLabelGuy

The DCT is a little quirky at times, but this is the nature of the beast. Sometimes the computer doesn't calculate the clutch slip-points just right or doesn't perfectly anticipate the drivers inputs.

I'm going to flash my ZCP's DCT to the GTS firmware this week. I'll report back on my findings.

Thanks let us know... Is the GTS dct flash better than stock?

CaryTheLabelGuy · 08-03-2016, 08:47 AM

Quote:

Originally Posted by Jerich0

Thanks let us know... Is the GTS dct flash better than stock?

It has higher clamping forces for WOT shifts, but as far as part throttle and normal drivability, I have no idea. I'll know soon.

OutlawX3M · 08-03-2016, 09:02 AM

It's more pronounced in D3 IMO -- in D2 & D1 I don't experience this.

I think it may also have to do with the circumstances of the stop compounded by the adaptives since it doesn't happen every time.

The DCT can be frustrating at times because of the adaptives IMO. There are times when I accelerate and I let off the accelerator at say 5.5k RPMs and it holds it while other times I can do the same thing it and it up-shifts (both in D3). So there's something different about what seems like the same driving that the DCT notices and acts differently. Maybe the angle of the throttle, or how fast I press it...IDK.

Trying to figure that out to be smoother...

EBM4 · 08-03-2016, 10:21 AM

Can you reset adaptions in the JB4 like the old Procedes? Mine occurred in D2 or D3 and only from 3 to 2

CaryTheLabelGuy · 08-03-2016, 05:00 PM

Quote:

Originally Posted by EBM4

Can you reset adaptions in the JB4 like the old Procedes? Mine occurred in D2 or D3 and only from 3 to 2

No. You'd need Rheingold (ISTA/D) to do that.

brian30tw · 08-03-2016, 08:31 PM

Mine does this as well. I swear it is worse after updating software to 59.0. I don't remember noticing it before that.

///Machiavelli · 08-03-2016, 08:50 PM

Have the same issue.

Took it in to the dealer but of course I couldn't reproduce it during a ride along with the shop foreman. He agreed to update the vehicle software (not sure if the whole car or just TCU was done).

It seemed like it was fixed but I got another rough, though not nearly as harsh, downshift again today.

Be very interested to hear Cary's experience with the VF TCU programming.

CaryTheLabelGuy · 08-03-2016, 08:55 PM

Quote:

Originally Posted by ///Machiavelli

Have the same issue.

Took it in to the dealer but of course I couldn't reproduce it during a ride along with the shop foreman. He agreed to update the vehicle software (not sure if the whole car or just TCU was done).

It seemed like it was fixed but I got another rough, though not nearly as harsh, downshift again today.

Be very interested to hear Cary's experience with the VF TCU programming.

I'm not doing the VF TCU flash. I'm flashing my TCU with the M4 GTS flash. VF Engineering claims their TCU flash isn't based on the GTS flash, but that remains to be seen.

I will let you know once I finally do it.

cryptz · 08-03-2016, 09:02 PM

Alex flashed mine to the GTS version, i still notice it.

kitesurfer · 08-03-2016, 09:34 PM

Quote:

Originally Posted by cryptz

Alex flashed mine to the GTS version, i still notice it.

Can you give some more info on how the GTS flash performs....I believe we all understand the clamping force increase, how is the driveability much improved over stock?, Better WOT shifts?, Better downshifts? , improved rev match? INYO is the flash worth it?

cryptz · 08-03-2016, 09:55 PM

honestly i do not notice a difference, i have a jbstage 1 and i am otherwise stock. its a little hard for me to know its even working but i watched alex do it. I would like to hear anyone else who did it though. I may be alone in my review of it. U cant really judge the clamping force in my case, but i havent noticed faster shifts etc, they were pretty much instant to begin with. i am always in sport+ manual mode also so its possible it doesnt change much in that mode.

aboulfad · 08-03-2016, 10:06 PM

Quote:

Originally Posted by kitesurfer

Can you give some more info on how the GTS flash performs....I believe we all understand the clamping force increase, how is the driveability much improved over stock?, Better WOT shifts?, Better downshifts? , improved rev match? INYO is the flash worth it?

No major noticeable differences based on my driving habits and compared with the prior 59.1 EGS stock software.

Quote:

Originally Posted by cryptz

honestly i do not notice a difference, i have a jbstage 1 and i am otherwise stock. its a little hard for me to know its even working but i watched alex do it. I would like to hear anyone else who did it though. I may be alone in my review of it. U cant really judge the clamping force in my case, but i havent noticed faster shifts etc, they were pretty much instant to begin with. i am always in sport+ manual mode also so its possible it doesnt change much in that mode.

Agreed... Same experience here. DCT behaves tad better in 59.x with infrequent "jerky" behaviour.

CreoUCLA · 08-03-2016, 11:31 PM

Quote:

Originally Posted by cryptz

i am always in sport+ manual mode also so its possible it doesnt change much in that mode.

If you're in manual mode all the time, that may be why you don't notice much difference.

I also have the GTS DCT flash, and I drove home in D3 to test it out (engine in Sport). All of the 3-2 down shifts were pretty smooth, whereas before the flash, I would experience jerkiness even in D1 and definitely in D2.

M4BUM · 08-04-2016, 01:25 AM

Quote:

Originally Posted by brian30tw

Mine does this as well. I swear it is worse after updating software to 59.0. I don't remember noticing it before that.

that is a important note
since my last service with an update to 59.0, i am sure it happens more often
before the update i had this 1-2 times in a month
now i have this 3-4 times in a week

but it is good to know, that it's nothing to worry about

the actual version released is 59.2
i hope in 60.0 the problem is solved

08-02-2016, 11:37 PM	#1
EBM4 Lieutenant 88 Rep 488 Posts Drives: 2015 BMW M4 Join Date: Mar 2015 Location: San Ramon CA iTrader: (3)	Rough downshift from 3 to 2 in Auto on a DCT Guys I'm getting a thought shift when coming to a stop from 3rd gear to 2nd gear Almost like the rev matching is note quite enough RPM's when the car shift down causing a jerk slowing the car down. Started after JB4 was installed. I'm running map0 or map2. Any ideas what the issue could be.
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08-03-2016, 07:15 AM	#2
M4BUM Private 32 Rep 59 Posts Drives: BMW M4 Join Date: Aug 2015 Location: Germany N iTrader: (0)	i have the same problem since day one. problem ist that it doesn't happen everytime. i have no tune etc. my dealer says that this is normal. maybe someone else has the same problem or has a solution?
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08-03-2016, 07:31 AM	#3
Kr3st Wheel Whore 539 Rep 796 Posts Drives: 2016 F80 M3 Join Date: Jan 2012 Location: Orlando iTrader: (0) Garage List 2016 BMW M3 [0.00]	I have same problem. It's happened since day one. Very annoying. I wonder if the GTS software or TCU flash fixes it. __________________ 2016 F80 M3: BBS FI-R \| JRZ RS-One \| ActiveAutowerke Full System including downpipes + Swain Coating \| ActiveAutowerke Active8 \| Maximum PSI Intake ^Build thread link \| Instagram \| Facebook
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08-03-2016, 09:02 AM	#7
OutlawX3M First Lieutenant 298 Rep 353 Posts Drives: 2016 BMW M3 ZCP. 2020 BMW X3M Join Date: Jun 2016 Location: Long Island, NY iTrader: (0) Garage List 2016 BMW M3 ZCP [0.00]	It's more pronounced in D3 IMO -- in D2 & D1 I don't experience this. I think it may also have to do with the circumstances of the stop compounded by the adaptives since it doesn't happen every time. The DCT can be frustrating at times because of the adaptives IMO. There are times when I accelerate and I let off the accelerator at say 5.5k RPMs and it holds it while other times I can do the same thing it and it up-shifts (both in D3). So there's something different about what seems like the same driving that the DCT notices and acts differently. Maybe the angle of the throttle, or how fast I press it...IDK. Trying to figure that out to be smoother...
	Appreciate 0 Quote

08-03-2016, 10:21 AM	#8
EBM4 Lieutenant 88 Rep 488 Posts Drives: 2015 BMW M4 Join Date: Mar 2015 Location: San Ramon CA iTrader: (3)	Can you reset adaptions in the JB4 like the old Procedes? Mine occurred in D2 or D3 and only from 3 to 2
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08-03-2016, 08:31 PM	#10
brian30tw Second Lieutenant 131 Rep 267 Posts Drives: F80 delivered in Munich Join Date: May 2012 Location: Chicago iTrader: (1)	Mine does this as well. I swear it is worse after updating software to 59.0. I don't remember noticing it before that.
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08-03-2016, 08:50 PM	#11
///Machiavelli Big Mac 121 Rep 494 Posts Drives: MY16 F80 Join Date: Sep 2011 Location: Canada iTrader: (4) Garage List 2016 BMW M3 [0.00] 2012 BMW 135i coupé ... [8.80] 2011 BMW 328i xdriv ... [0.00] 2015 BMW X5 35i [0.00]	Have the same issue. Took it in to the dealer but of course I couldn't reproduce it during a ride along with the shop foreman. He agreed to update the vehicle software (not sure if the whole car or just TCU was done). It seemed like it was fixed but I got another rough, though not nearly as harsh, downshift again today. Be very interested to hear Cary's experience with the VF TCU programming.
	Appreciate 0 Quote

08-03-2016, 09:02 PM	#13
cryptz Lieutenant 172 Rep 435 Posts Drives: 2015 m4 Join Date: Jun 2014 Location: pottstown pa iTrader: (1)	Alex flashed mine to the GTS version, i still notice it.
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08-03-2016, 09:55 PM	#15
cryptz Lieutenant 172 Rep 435 Posts Drives: 2015 m4 Join Date: Jun 2014 Location: pottstown pa iTrader: (1)	honestly i do not notice a difference, i have a jbstage 1 and i am otherwise stock. its a little hard for me to know its even working but i watched alex do it. I would like to hear anyone else who did it though. I may be alone in my review of it. U cant really judge the clamping force in my case, but i havent noticed faster shifts etc, they were pretty much instant to begin with. i am always in sport+ manual mode also so its possible it doesnt change much in that mode.
	Appreciate 0 Quote