DCT lurch/surge in first gear while in D mode

[dmboone25]

Originally Posted by uniqueMR

Welcome to BMW DCT. Normal behavior.
Porsche PDK, is smooth as a butter

Agreed. Never had this problem with the PDK.

[2kaccordocoupe]

The PDK logic is different from that of the DCT that we have in our cars.

Once you take your foot of the brake in a PDK it will begin to move, much like your traditional auto tranny.

When you take your foot off the brake in our DCT the car won't move until you apply some gas.

By having the computer apply the throttle the response is much smoother and predictable.

[SpaceCowboy]

Mine does this too. Always has. I think it is just a downside of the DCT.

[BMWM5NYC]

I think a lot of people who are experiencing this have never driven a Manual car. If you accelerate in 1st with a stick at these RPMs and then clutch in without shifting when the drive train disengages you will get the same lurch. Also with the gear ratio of first gear you will get this same lurch if you just let of the gas abruptly. This is a characteristic of a Manual transmission. Your DCT performs like a manual transmission with an automatic mode.

[drgmt]

This happened to me after a recent software update.

GTS DCT flash and the car is transformed. So smooth and no lurching at all. Transformed the car !

[Aapparition90]

Originally Posted by Modaddict79

This happened to me after a recent software update.

GTS DCT flash and the car is transformed. So smooth and no lurching at all. Transformed the car !

I highly recommend this as well despite it sounding too good to be true sort of a thing its not , Just do it . I run it in conjuction with the cs tune.

[drgmt]

Originally Posted by 328ihp

I highly recommend this as well despite it sounding too good to be true sort of a thing its not , Just do it . I run it in conjuction with the cs tune.

I was gonna sell the car to be honest. This update made me keep it

[BlatantMaple854]

Originally Posted by Modaddict79

I was gonna sell the car to be honest. This update made me keep it

I hear y’all 100%. But will this void my warranty?

[drgmt]

It will void your gearbox warranty yes.

But I couldn't care less to be honest. My car was bloody terrible without it. So I had no choice.

[BlatantMaple854]

One last thing I need to ask about this topic.

Since the update, I feel as though my DCT is much noisier as well as the rear diff. I can literally hear an audible click type noise for every downshift in auto mode from 4-1 gears. Also, the diff or driveshaft occasional had a thud when coming to a stop from 2-1. Now, I feel it much more frequently and usually twice. Once from third to second and second to first.

Is this normal behavior and I’m just looking for an issue? Or, should is there something mechanical that could be going wrong.

Also, to clarify, I did not consent to a software update. My bmw tech did it to, I assume, solve another issue.

[valeram]

I did remember that my 2013 E92 M3 had that problem before. I sold it and got myself a Macan Turbo. The PDK is way smoother and better. I just ordered a 2018 M3 for ED and hoping that this DCT issue has been taken care of. It looks like the issue is still existing. It is not a deal breaker though, just hoping.

[domino_z]

Exact same problem on my late 2016 built zcp after installing latest pszdata trans sw

Feels like clutch slip - slight over rev then lurch as clutch bites. does it worse starting on hills. it's not actually hw slip, as stated in more aggressive modes it will move off from rest without the lurch

The new sw is so much smoother than my original '16 sw, I think it's just backing off the clutch capacity to smooth it out, and it's prob gone too far in D1. If you use a heavy throttle in D1 it won't do it as the tcu will be sending more cc - i've built enough dual clutch box's to recognise the problem

I did the adaptation reset (accelerator pedal down for 25 seconds), and it seems to have fixed it, but since it'll relearn it'll most likely come back

Gts sw which is an older version than I have now, and theoretically should have higher cc across the board, I would assume will sort it

[domino_z]

update - didn't take long for slip/jerk to come back after adaptation reset

seems to be worse when cold first thing in morning

will try the gts coding to see if my theory on higher cc is correct

[gixxerboy63]

Where can you get GTS coding?
...and why would it void the transmission warranty?

[Thescout13]

Originally Posted by gixxerboy63

Where can you get GTS coding?
...and why would it void the transmission warranty?

Why would a transmission warranty be voided when the transmission is coded or tuned beyond its spec for that specific car so that it has different shift points etc? Idk that's a hard one.

But seriously, if you do anything to your car that is not OEM and/or done by dealer it can technically void the warranty for that thing (yes a dealer may have to prove it in court that the changed caused a failure, but that's an easy bar). So you tune a transmission to act like the one in a different car, the dealer will see that, and use it to void the warranty for that transmission