My SA called me today that they may have received the new software that is suppose to fix the 2-1 down shift jerk for SAT when coming to a stop. He says that he will double check to see if this indeed will cure the "jerkiness" in some of our 550s with SAT. Hope to make an appointment soon and get it updated. Anyone else hear about this software?

 

Have not -- but please keep all of us SAT owners updated!!

 

I'm headed in next week for a recently released software update to retroactively remove the soft-stop function (at least that's how it was explained to me by the master tech.) This is supposed to help with the harsh braking, but nothing to do with the transmission to my knowledge. Ironically, I just contacted them via email to request a transmission diagnosis as well because of my displeasure with the harsh downshifts. I'll keep you posted, but I'm not too optimistic. Since your post specifically references the 2-1 shift, does that indicate that your car is only jerky in SPORT/DS mode? It is certainly worse for me in either of those modes, but does often appear in D as well (which to my understanding only goes to 2nd gear.)