Just to chime in... I had the same issue come up late last year -- the violent 2 -1 shift from a rolling stop, or even when the car was stopped. It felt like I was hit from behind by a bus. The dealer reflashed the transmission software saying it's a common issue.

Now (4-5 months later), it seems to be back. Not nearly as bad, or it may be that I'm now more careful and watch my takeoffs more closely...

Does the hold the gas pedal down for 30 seconds method work?

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2005 BMW X5 4.4 Sapphire Black/Sand, Sport, Premium, Cold Weather, Rear Climate, Bluetooth, Sirius, Rear Airbags, Heated Rear Seats, Heated Steering Wheel, Premium Hi-Fi, Tow Package