Two problems related to power train have been reported for the 2009 BMW M3. The most recently reported issues are listed below.
Hello. I have a 2009 BMW M3 with the dct transmission. I am experiencing significant delays when down shifting from one gear to a lower gear. The problem occurs when you slow down, like for a turn, but do not come to a complete stop. The dct transmission seems to have a serious problem figuring out what gear to select because when you step on the gas to accelerate, there is a very significant delay in the power engaging. I would say about 2-4 seconds. By this time, I am really stepping on the gas pedal. The transmission finally picks a gear, which results in the car suddenly lurching forward, sometimes engaging the anti-skip control. This problem becomes most apparent when making a turn into on-coming traffic, slowing down to around 10-15 mph. After the turn, the car is positioned in the traffic lane, but I have no power to accelerate into the flow of traffic. The oncoming cars are now closing in on your car at a fast rate, and you're basically stuck.
There's a significant lag for the transmission to engage in my car which at times prevents me from getting out of the way of a potential conflict.