I went to 3 transmissions shops including lexus. @ told me it was the transmission. But Lexus said it may be the control box. The first was to replace to transmission labor for $1200. I get my own transmission.The second wanted 4000 because I couldn't order my own transmission. Lexus wanted $4,8000 but lexus also told me that they recommend the control box first for $2500. Then if not, the transmission. That was out of the question so I went with the first one.Brought a transmission for $1,300. they replaced my transmission and it still jerked.

So while on ebay look for an ECU I found a few for way less than $2500. then I found a site that repairs ECU's for $150. What do I have to lose? I sent my ECU to them and in a week they had it back to me. The technician put in in for free because anyone can do it. He unclipped 2 buttons and it came out but he charged me $70 to take it out before I knew it was so easy. They put it in my car and my car ran perfectly and have ever since. I lost loads of money but I hope this post spare you of the frustration I experienced. Sia Electronis is the place.