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My friend bought an M3 with the DCT transmission and the tranny is acting strange, on rapid downshifts it gets confused and will only select the odd gears....also, when slamming on the brakes the transmission/engine failure light comes on and the car will not downshift....every so often it will not upshift to even gears either.
 

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I'm not familiar with the DCT, but it sounds like the ECU is doing the driving...not your friend.

BMW makes sure to program in "fail-safes" in the ECU to prevent high stress on the tranny/engine. If you're rapidly down shifting (while actually driving, not stopped), the ECU might be going "whoa, whoa, whoa....that is crazy!!! Let me do this instead."

I haven't heard anything particularly bad about the DCT. Actually, it's mostly good things i hear. Either way, if it's an e92 it's hopefully still under warranty, just bring it to BMW and describe the problem. They'll plug in and check to see if there's anything out of the ordinary.
 

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I'm not familiar with the DCT, but it sounds like the ECU is doing the driving...not your friend.

BMW makes sure to program in "fail-safes" in the ECU to prevent high stress on the tranny/engine. If you're rapidly down shifting (while actually driving, not stopped), the ECU might be going "whoa, whoa, whoa....that is crazy!!! Let me do this instead."

I haven't heard anything particularly bad about the DCT. Actually, it's mostly good things i hear. Either way, if it's an e92 it's hopefully still under warranty, just bring it to BMW and describe the problem. They'll plug in and check to see if there's anything out of the ordinary.
+1,
The car wont let you rapidly downshift if doing so may cause the car to go above redline. you need to be at the correct speed to downshift into that gear, and rapidly downshifting usually doesnt mean you are at the right speed. Also, does your friend know how to adjust the shift speed and all that?
 

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Discussion Starter #4
I'm not familiar with the DCT, but it sounds like the ECU is doing the driving...not your friend.

BMW makes sure to program in "fail-safes" in the ECU to prevent high stress on the tranny/engine. If you're rapidly down shifting (while actually driving, not stopped), the ECU might be going "whoa, whoa, whoa....that is crazy!!! Let me do this instead."

I haven't heard anything particularly bad about the DCT. Actually, it's mostly good things i hear. Either way, if it's an e92 it's hopefully still under warranty, just bring it to BMW and describe the problem. They'll plug in and check to see if there's anything out of the ordinary.
took it to BMW and nothing odd came up on paper.....
 

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Discussion Starter #5
+1,
The car wont let you rapidly downshift if doing so may cause the car to go above redline. you need to be at the correct speed to downshift into that gear, and rapidly downshifting usually doesnt mean you are at the right speed. Also, does your friend know how to adjust the shift speed and all that?
Doesn't happen, I.E. on the highway at 65mph in 6th at 3k rpm, if he wants to pass he will downshift twice then get on it a little bit. These 2 consecutive downshift are too fast it seems and the CPU will put it in 7th, dangerous if you pull out in front of someone.....
 

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its normal... dont worry about it...
 

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Doesn't happen, I.E. on the highway at 65mph in 6th at 3k rpm, if he wants to pass he will downshift twice then get on it a little bit. These 2 consecutive downshift are too fast it seems and the CPU will put it in 7th, dangerous if you pull out in front of someone.....
Very strange...driving like that 2 quick clicks to downshift to pass someone would put me in 4th unless I was already at high rpm's then it may only shift down to 5th never downshifted and had a higher gear engage. What did BMW tell him when he brought it in did he explain the whole situation?
 

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Discussion Starter #8
Very strange...driving like that 2 quick clicks to downshift to pass someone would put me in 4th unless I was already at high rpm's then it may only shift down to 5th never downshifted and had a higher gear engage. What did BMW tell him when he brought it in did he explain the whole situation?
I was not with him when he took it in, he just complains about it whenever we talk cars....I can ask him for a verbatim report though.....
 

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what year is it?? i know there was Software updates for the DCT on the 08 models. maybe it just needs a software tweak
 

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Doesn't happen, I.E. on the highway at 65mph in 6th at 3k rpm, if he wants to pass he will downshift twice then get on it a little bit. These 2 consecutive downshift are too fast it seems and the CPU will put it in 7th, dangerous if you pull out in front of someone.....
Sounds like your buddy needs a crash course on what a redline and why a car throws an EML code if you live by it too much :whistle:
 

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Discussion Starter #11
what year is it?? i know there was Software updates for the DCT on the 08 models. maybe it just needs a software tweak
He has had all software updates....
 
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