My x5 skips and sutters when accelerating ...when it hits third gear..is when I get the sutters ...goes away as i gas it/accelerate ...does not happen in sport mode or manual step mode?...engine?...transmission?..torque converter....how can i fine out for sure what is happening....the dealer say let them plug it up for 150.00...and the code will tell them and that they have the latest software and better than say my local bmw repair specialist?...thanks so much jeff atlanta