Shuddering between 1st and 2nd when warmed up

Hi all. I have a 2006 Lexus is250 that is approaching 300k miles. After driving for about 20 minutes, the car will shudder when going from first to second at a low acceleration when I’m in stop and go traffic. The engine also stalls when I shift into reverse when parallel parking after an extended ride or when coming to a stop while in snow mode. I had the problem for a few months when I got the code “P2757 Torque Converter Clutch Pressure Control Solenoid Control Circuit Performance or Stuck Off,” after a stall. I got a full transmission rebuild but it didn’t seem to fix the problem. I was told it is a computer issue by the transmission shop. Took it to a Lexus dealership, they couldn’t find anything wrong with it. Any ideas before I bring it into another shop? Thanks.

Get another opinion. Something is wrong with the torque converter so hopefully the next shop can give you a proper diagnosis.

That is my guess as well, but considering I brought the car in with that code and got a complete transmission rebuild, the torque converter problem should have been taken care of correct?

"P2757 Torque Converter Clutch Pressure Control Solenoid Control Circuit Performance or Stuck Off,

That code does not condemn one item in the transmission. It includes all the electronics that control the torque converter lock up. It could very well be an electronic problem(computer) or any of the wiring/sensors going to and from it. Sounds like the shop that did the rebuild didn’t dig far enough to uncover the actual cause.

Was a new torque converter installed when the transmission was rebuilt? Your invoice should itemize that part seperately.

It better have been, I didn’t even consider that. That’s what I went in for and then left with a whole transmission rebuild. When I’m able to bring it in next week to a different shop I will have them check.

You paid $3000 for rebuild? When? Why can’t you ask shop that did work? I certainly expect a 12 mo warranty at least on any trans overhaul.

One of the national transmission chains charged my daughter $2,700 to overhaul the transmission on her Jeep Cherokee but all they actually did was replace the speed sensor. When I investigated the situation it appeared that such thievery was common.

you have code. Shop says an overhaul will fix worn mechanical issues that cause code. Overhaul does not fix issue. Shop says it must be computer issue. A bad BCM? Some cars have trans computer. Some use engine PCM or ecm for shifting. Dealer says BCM is fine? Any shop can make a mistake on trans overhaul. They can certainly miss some things. A worn seal that allows pressure to bleed/bypass some circuit? A worn bore in valve body? A funky new converter? 300 k miles is plenty to cause worn components.