335is DCT.. From launch computer will shift to 3rd gear instantaneously right after 1-2 gear shift?

Mvaccarelli01

Corporal
Apr 18, 2020
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73
0
Testing the launch control only on launches from 1st gear when the car shifts to 2nd gear it will shift to 3rd gear by itself way to early in the rpm range.
It doesn't matter if its in M-mode or when i launch it and throw it in D to shift by itself right after launch. It will launch and shift to 2nd gear but will shift to 3rd almost right away after 2nd.
I experienced this at the track but the issue didn't happened on wastegate pressure only when i turn the boost up enough.

here is 2 log showing examples https://datazap.me/u/mvaccarelli/dct-issue?log=1&data=3-17
do you have any idea why the car shifts to 3rd by itself regardless? if i start the car from 2nd I can rev it all the way through the range. It only happens when launching from 1st gear.
i can be in Manuel mode or throw it in drive mode after launch wont let me rev all the way through 2nd gear.
 

houtan

Lieutenant
Nov 2, 2017
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135i N55 DCT; PS2
It’s the auto shift at redline. When the wheels are spinning and the revs shoot up fast the car auto shifts. Happens on my 135 as well. It’s Super annoying. That’s why I am praying all the smart people in this forum figure out a way to disable it or to get the M hw or sw working with the 2.56 diff. The M cars don’t auto shift.
 
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Mvaccarelli01

Corporal
Apr 18, 2020
121
73
0
It
It’s the auto shift at redline. When the wheels are spinning and the revs shoot up fast the car auto shifts. Happens on my 135 as well. It’s Super annoying. That’s why I am praying all the smart people in this forum figure out a way to disable it or to get the M hw or sw working with the 2.56 diff. The M cars don’t auto shift.
its so werid because it doesn’t even feel like the tires spin that much at all it literally shifts to second and even continues for another 500-1000 rpms to around 5500 and then shift to 3rd it’s so stupid lol
 

aus335iguy

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Nov 18, 2017
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I believe this to be a function of the DSC and moving to M3 or 1M DSC will fix it. It’s a flash away fellas ;)
 

aus335iguy

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Nov 18, 2017
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The DSC broadcasts road speed which is measured at the wheels. As long as it’s what your TCU expects you should be ok.
 

ganque

Specialist
Jan 22, 2018
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BMW 135i N55 DCT pure stage 2
I believe this to be a function of the DSC and moving to M3 or 1M DSC will fix it. It’s a flash away fellas ;)
Is it like the EGS module flash via winKFP?
If so, what's the DSC module version in WinKFP and which zsub family number needs to be changed?
 

aus335iguy

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Nov 18, 2017
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Is it like the EGS module flash via winKFP?
If so, what's the DSC module version in WinKFP and which zsub family number needs to be changed?
Essentially yes but its a little more involved than that. Its a forced flash in expert mode and you have to change the VO first before you can code
Once you have flashed you also need to rewire the DSC button to disable DTC. The SZL may also need to be changed but apparently per other comments the SZL may work regardless.
 
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aus335iguy

Colonel
Nov 18, 2017
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Correction you can code the CIC to disable DSC per my comments. You don’t need to rewrite if you just want to try it
 

aus335iguy

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Nov 18, 2017
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XHP said short shifting is a function of throttle changes in the DME. Ask your tuner to change your settings back to stock. Try that?