They check the car and update PCM software and they told me the problem is fixed. I tested and the delay is gone, and when coming to stop the downshifting is not that noticeable now. I think maybe in 2015 model they fix the issue but still need software update or something. I will be going to dealership next week again to replace the bluetooth module. Thank you mike,pdlpsher,and craigo。
Thanks for reporting back and glad they got you all spruced up! Mine hasn't needed any software updates or calibration and I have good throttle, shifting, braking and MPG so I haven't had it to a shop since it was new in 2012. But it sounds like it just needed a little re-calibration.
I assume your bill was $0.00?