Very strange shift happening?

[Wanna Race?]

Has anyone had a problem with an almost complete loss of power for about 1 second when switching from first to second gear on a DTC? It has happened to me about 5-6 times since I got the car in July, it only happens while I am shifting while slightly turning and the car is cold. It almost feels like the traction is kicking on and then there is a delay for a second before the engine puts power to the tires again. ANy help or comments are appreciated. Thanks

[MSPORTWORLD]

1 second is a pretty long time...when cold there does seem to be a lag in power application for the 1-2 shift. It goes away by the time I leave the development though. Normal from what I can tell.

[IMG]

What year is your car ?

[CBS]

Originally Posted by img

What year is your car ?

I thought the same thing since I had a 2008 M3 w/DCT but OP lists he drives a 2011 M3 w/DCT. I am at a loss for a suggestion.

[Wanna Race?]

I have a 2011, ZCP. It only does this while I am slightly turning and accelerating. It does not happen driving strait.

[IMG]

Originally Posted by CBS

I thought the same thing since I had a 2008 M3 w/DCT but OP lists he drives a 2011 M3 w/DCT. I am at a loss for a suggestion.

Originally Posted by Wanna Race?

I have a 2011, ZCP. It only does this while I am slightly turning and accelerating. It does not happen driving strait.

You might want to get your cars to the dealer and get the latest DCT tune. some of the 08s have a lag between shifts which the newer DCT tunes fixes that but BMW just released a new DCT tune to fix other things and may be you might want to get that !

[VictorH]

I wonder if you are talking about the bucking that some people have (I get it sometimes too) when the car is cold and you are just starting off. It might be exacerbated by shifting from 1st to second gear. I never had this problem until I got the latest software "update" and I'm willing to bet it's the cold start engine enrichment that has been leaned out for emissions reasons so that when the engine is cold and it's cold outside the motor doesn't really have enough fuel and cuts out. I've experienced this but only on rare occasion and it's certainly not one second long, perhaps a quarter second and the car bucks pretty hard.

[Wanna Race?]

Originally Posted by VictorH

I wonder if you are talking about the bucking that some people have (I get it sometimes too) when the car is cold and you are just starting off. It might be exacerbated by shifting from 1st to second gear. I never had this problem until I got the latest software "update" and I'm willing to bet it's the cold start engine enrichment that has been leaned out for emissions reasons so that when the engine is cold and it's cold outside the motor doesn't really have enough fuel and cuts out. I've experienced this but only on rare occasion and it's certainly not one second long, perhaps a quarter second and the car bucks pretty hard.

Ok, maybe the timing was off, but it was exactly what you explained and it happens very rarely as well. I do have the latest software, I worked at he dealer for a year and just left, also I live across the street, thank god.

[MKE_M3]

probably is traction control

[Novus]

I've had the same thing happen to me and I just had the DCT software updated in December. It only occurs when shifting from 1st to 2nd during a sharp (90deg) turn and trying to accelerate, let's say briskly. I've had it happen both when the engine is cold and at normal operating temperature. I do not remember seeing the traction control light come on. The clutch feels like it is fully engaged, but the throttle control seems to cut out. As soon as the front wheels are pointed in pretty much the same direction as the rear wheels (say ~5deg) everything returns to normal.

It does not feel like traction control normally does when it kicks in. There seems to be some slip allowed when traction control turns on normally. This is very different as it is a nearly complete loss of power for a good second as the OP described.

It could be some kind of perfect storm as far as the system is concerned (Engagement of 2nd gear, desired throttle position, steering angle, etc.) where everything comes together to make it think there is some catastrophic loss of traction. However, I am not an expert on the intricacies of the traction control system.

My temporary solution is to remain in 1st until the wheels are pretty much pointed in the same direction or to shift to 2nd much earlier in the turn if the opportunity to do so is there.

I work with software developers and there is always the chance that fixing a major issues like the original DCT software issues uncovers or causes some undesired secondary issues. Maybe this is one of those cases.

I'll ask my dealer about it the next time I go in, but it's good to know that this isn't just me.