Auto tranny problem (I think !?)

[Alex]

OK this is my first post. I have been lurking on this website for about a year now. I got a question about my car. First off its a 2001 GT Auto (yeah I know first mistake) well anyway this is the problem. I cruise along in overdrive and everythings fine, now if I have to slow down for one reason or another and then push on the gas to speed back up the car will jerk (down-shifting I guess) when i push on the gas pedal. Sometimes it jerks harder then others. This also happens when I am accelerating out of a turn. I can feel when its going to happen (there is a feeling almost like the car has no power). Now If i see it coming where I would have to slow down I sometimes turn overdrive off (shift into third) then slow down, accelerate, flip overdrive back on and no jerking. Please help I dont know if this is normal. My last car was a Ford probe and the tranny broke at 55,000 miles. The celica has about 25000 miles on it now. Thanks in advance

[gto78]

There may be a problem with the torque converter clutch (TCC). It sounds like its not disengaging when its supposed to. You can do a small test that will help the repair shop a little bit before you take it in. Drive at a steady 55 mph and look at the tachometer. make sure everything is steady, no varying rpms. Then while holding your foot on the gas take your other foot and very lightly press on the brake pedal, but not enough for the car to start slowing down. When you are watching the rpms they SHOULD jump UP about 200-300 instantly when the brake pedal is pressed. This tests the switch circuit from the brake light switch to the transmission TCC solenoid. If the rpms went up then thats good.

I have a gt-s auto and it does that sometimes (what your describing). The worst case would be that you'll stop at a light and the car will stall. Its like forgetting to step on the clutch in a manual tranny. Mine also does that once in a while.

[TRD GT-S]

i had the same problem driving home one day along the interstate....i would downshift in my auto gts and then shift into 4th and it would jerk a slight bit....but the problem has seemed to disappear the next day???

[Nightrider]

Try resetting ECU

[Alex]

Thanks for all the help guys. I tried the brake tapping and the rpms do seem to jump up a little when i tap on the brake (There maybe is a slight delay) Im going to try resetting the ECU tomorrow. Thanks again for your help Ill post back with updates to tell you what happend.

Alex