DCT bogged down and switched to Neutral

  • Login or Register, members don't see Ads!
  • Tip: You can toggle the Dark Theme at the bottom of the page
May 14, 2018
47
Good morning all.

This morning had a strange issue where at the traffic light on myvwaybto work, I pulled off like normal but as i touched the gas the car lurched/bogged and went to Neutral.
I immediately switched the lever to D and took off again fine.

The car often bogs on pull away. The feeling is almost like a stall. Touch the gas, soon as the car wants to move off, the car feels like it wants to stall then iff it goes again. Sometimes it's so severe that I see the Cluster needles sweep (JB4), so it's like the car restarts in a sense, but I dont have to restart the engine.

I have the 8609092 software loaded, however I had this issue previously on the stock DCT software also.
Previously i did have BMW update the entire car they did say that the TCU software was done also. But i cant be sure, can only take their word on it.

Anyone have this ever at all on their DCT?
My car drives beautifully otherwise. It's just the damn initial pull away. Sometimes its butter smooth. But other times it has that bog/almost stall. Cant explain it any other way.

Thanks in advance.
 

aus335iguy

Lieutenant
Nov 18, 2017
993
This doesnt soun like a DCT issue to me at all. This sounds like you have an electrical issue. Have you tried removing the JB4 to see if it or its wiring could be causing it ?
 

aus335iguy

Lieutenant
Nov 18, 2017
993
COme to think of it, its happening when youre pulling away at the lights. I think i read somewhere that someone found an issue with lurching and it turned out to be engine mounts... ill see if i can dig it up ...
 
May 14, 2018
47
This doesnt soun like a DCT issue to me at all. This sounds like you have an electrical issue. Have you tried removing the JB4 to see if it or its wiring could be causing it ?
No I havent yet removed the JB4 for this testing. Will have to attempt that the weekend.

Will wait on your thread that you find regarding Engine mounts. Quite keen to read that.

Thank you.
 

aus335iguy

Lieutenant
Nov 18, 2017
993
Good news, I found the thread! Bad news... it was you, the last time you posted in here

Start by removing some variables. CHeck the usual electrical suspects.
 

RSL

Sergeant
Aug 11, 2017
391
MAP sensor set correctly? Incorrect conversion can randomly exhibit that behavior from a stop depending on conditions. If you have a 3.5 bar and JB4, need to leave the bin stock for the MAP (don't change conversion in rom or select MHD 3.5 bar flash option) and only set the 3.5 bar option in JB4.

Short of that, I'd pull the JB4 to test (and never put it back in), in which case, you will want to set the 3.5 bar conversion in the rom or use the MHD option with the flash if you have a 3.5 MAP.
 
May 14, 2018
47
MAP sensor set correctly? Incorrect conversion can randomly exhibit that behavior from a stop depending on conditions. If you have a 3.5 bar and JB4, need to leave the bin stock for the MAP (don't change conversion in rom or select MHD 3.5 bar flash option) and only set the 3.5 bar option in JB4.

Short of that, I'd pull the JB4 to test (and never put it back in), in which case, you will want to set the 3.5 bar conversion in the rom or use the MHD option with the flash if you have a 3.5 MAP.
Thanks. Been reading about the Map Conversion. But since I have JB4 I assume it doesnt have to be done.
I still have stock N54 TMAP.
I tried the 3.5bar and adaptor I have. Works fine. I just always have the 2ABC and 3100 codes when reading for faults. Even though the car drives perfectly. Those codes are always present.

I've read alot of your threads. And I'm trying to learn as much as i can from your tuning experience.
So far I've just made adjustments to my Pump flash for the Disable Tq reduction by Ign toggle.
And the
Basic corrections and Cehsicle speed corrections tables for the throttle sensitivity. Just those have made a good difference.
Want to learn how to increase the clutch pressures for my DCT via the torque tables. Still trying to find more on that.
 

RSL

Sergeant
Aug 11, 2017
391
Thanks. Been reading about the Map Conversion. But since I have JB4 I assume it doesnt have to be done.
I still have stock N54 TMAP.
I tried the 3.5bar and adaptor I have. Works fine. I just always have the 2ABC and 3100 codes when reading for faults. Even though the car drives perfectly. Those codes are always present.

I've read alot of your threads. And I'm trying to learn as much as i can from your tuning experience.
So far I've just made adjustments to my Pump flash for the Disable Tq reduction by Ign toggle.
And the
Basic corrections and Cehsicle speed corrections tables for the throttle sensitivity. Just those have made a good difference.
Want to learn how to increase the clutch pressures for my DCT via the torque tables. Still trying to find more on that.
If you're using the stock MAP sensor, nothing needs to be done. Any time you're using the 3.5 bar with JB4 though, you have to enable it in JB4 only. Don't do anything for it in the BEF. If you're flash only and 3.5 bar, must make the change in the flash. If it's not set correctly, you can get the 2ABC and can have similar issues, usually at standing start.

Changing the pedal value tables also changes everything down the line and could be a contributing factor to the standing start issue. I'm still tinkering with them, but offset with torque output request to keep increased rev movement without output having a similar movement increase.

Everything runs through the JB4, could be something as simple as a loose connection or board going bad. As @aus335iguy said, try a stock BEF/pedal value tables and if it's still occurring, narrow it down by removing easy potential avenues of failure (JB4). If it stops occurring with stock pedal values, probably need to make some adjustments elsewhere to make it play nice.

Raise load to torque values to increase clutch torque target/pressure. I generally keep all 3 L2T tables the same. For a general move higher, it's easiest to lower the load break points in the area you want to increase (i.e. around WOT actual load), assuming the tables are stock and your WOT actual load is currently below higher L2T load rows. You'll want to raise torque monitor ceiling with it to keep room with the increase. There are other tables that affect it, but L2T is the usual starting point.

Don't go crazy with huge changes. Move a bit, log, adjust.
 
May 14, 2018
47
If you're using the stock MAP sensor, nothing needs to be done. Any time you're using the 3.5 bar with JB4 though, you have to enable it in JB4 only. Don't do anything for it in the BEF. If you're flash only and 3.5 bar, must make the change in the flash. If it's not set correctly, you can get the 2ABC and can have similar issues, usually at standing start.

Changing the pedal value tables also changes everything down the line and could be a contributing factor to the standing start issue. I'm still tinkering with them, but offset with torque output request to keep increased rev movement without output having a similar movement increase.

Everything runs through the JB4, could be something as simple as a loose connection or board going bad. As @aus335iguy said, try a stock BEF/pedal value tables and if it's still occurring, narrow it down by removing easy potential avenues of failure (JB4). If it stops occurring with stock pedal values, probably need to make some adjustments elsewhere to make it play nice.

Raise load to torque values to increase clutch torque target/pressure. I generally keep all 3 L2T tables the same. For a general move higher, it's easiest to lower the load break points in the area you want to increase (i.e. around WOT actual load), assuming the tables are stock and your WOT actual load is currently below higher L2T load rows. You'll want to raise torque monitor ceiling with it to keep room with the increase. There are other tables that affect it, but L2T is the usual starting point.

Don't go crazy with huge changes. Move a bit, log, adjust.
Thank you RSL, will go over this post again and again.
I have the JB4 so itll just be the parameter change in the User Adjustments tab on JB.

For the L2T tables, i will play around and test, i do have the N54 Tuning Guide spreadsheet as well, how up to date that is, i am not sure, but i think it will be a good base to learn from. i will take your points into consideration as well.

Appreciate your feedback Sir.
 

RSL

Sergeant
Aug 11, 2017
391
What is your menu 11 set to on JB4? If it's high, try a low-midrange (more linear request) setting.
 

RSL

Sergeant
Aug 11, 2017
391
I would, just to rule it in/out. It will feel dull, but I'd go minimum/close to minimum just to see.
 
May 14, 2018
47
Noted. Will absolutely set that when I get in the car in the morning on my way to work. Thank you sir.
Will update to by the end of the day with the feel.
 

RSL

Sergeant
Aug 11, 2017
391
If it still does it on standing start, try to catch one in a log and post here.
 
May 14, 2018
47
HI there RSL, ive made the settings as suggested, and it seems to have been corrected, however i have also changed my driving style, i now take my foot off the brake and allow the car to take onto the clutches and move forward before applying the throttle.
previously if i let off the brake and go straight to the Throttle it does the bog feeling, i can test it again, but for now it feels good, alot smoother actually.
 
  • 1Like
Reactions: RSL
May 14, 2018
47
That's not a bad thing, I wish I didn't lol
LOL, do you guys hate JB4 that much? please tell me why. honestly speaking.
my current gripes:
every startup has a wastegate rattle, but no rattle while driving.
the menu 11, 12 settings to dial in are a nightmare, still have slight oscillation every now and then in 2nd gear on light partial throttle.
Im sure there a few more, but i cant think right now.

Back to me issue, still bogs if i try move quickly from Brake to Gas, havent tried to capture in a log yet, but will do this when im back home and drive the car as im travelling right now.

I know you guys dont like JB4, but im using it for the Meth controlling, do any of you have experience with menu 4/4 to use JB to control Meth, and use Flash only?
 

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Top