# Rav4 ECM question **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** rav4, toyota\ **Created:** [February 10, 2010, 9:23pm UTC](https://community.cartalk.com/t/rav4-ecm-question/44247 "2010-02-10T21:23:48Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Chigirl1964](https://avatars.discourse-cdn.com/v4/letter/c/6a8cbe/32.png) [@Chigirl1964](https://community.cartalk.com/u/Chigirl1964)\ **Post date:** [February 10, 2010, 9:23pm UTC](https://community.cartalk.com/t/rav4-ecm-question/44247/1 "2010-02-10T21:23:48Z")
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? ---
**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\ **Post date:** [February 10, 2010, 9:42pm UTC](https://community.cartalk.com/t/rav4-ecm-question/44247/2 "2010-02-10T21:42:48Z")
And, you think that it is the transmission which is BUCKING because…? ---
**Author:** ![Chigirl1964](https://avatars.discourse-cdn.com/v4/letter/c/6a8cbe/32.png) [@Chigirl1964](https://community.cartalk.com/u/Chigirl1964)\ **Post date:** [February 10, 2010, 11:22pm UTC](https://community.cartalk.com/t/rav4-ecm-question/44247/3 "2010-02-10T23:22:31Z")
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. ---
**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\ **Post date:** [February 10, 2010, 11:44pm UTC](https://community.cartalk.com/t/rav4-ecm-question/44247/4 "2010-02-10T23:44:25Z")
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. ---
**Author:** ![Chigirl1964](https://avatars.discourse-cdn.com/v4/letter/c/6a8cbe/32.png) [@Chigirl1964](https://community.cartalk.com/u/Chigirl1964)\ **Post date:** [February 11, 2010, 1:05am UTC](https://community.cartalk.com/t/rav4-ecm-question/44247/5 "2010-02-11T01:05:49Z")
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…