Rav4 ECM question

I saw earlier emails about the ECM needing to be repaired/replaced due to programming problem. I had this done by Toyota 3 years ago when the service bulletain was first sent out.

About a week ago My 2002 Rav4 started “bucking” when I put the transmission in reverse (180K)

It is time for the fluid to be drained/replaced but now I’m worried the ECM is starting to go bad - any thoughts?

And, you think that it is the transmission which is BUCKING because…?

Hellokit - I think it’s the transmission because it only happens when I shift from park to reverse. It’s slightly less noticeble when I shift from drive to reverse (after to coming to a complete stop of course) - but it’s still there.

Is there perhaps another reason for this iso the transmission? I certainly would appreciate any information someone might have.

I doubt the ECU is causing the bucking problem. Hopefully the fluid change will correct the trouble but if not perhaps the trouble is with a bad solenoid or valve in the transmission. There is a product called Trans-X that folks have used with good succuss to clear valve troubles.

Thank you both for your input. I was starting to sweat bullets when I tried to find a similar chat and found the ECU/ECM link. Betty (that was I call my car) has been very good to me all these years and I was hoping the ole’ girl wasn’t starting to go down the drain…