Hi guys, I've been doing a lot of reading to try and figure out what might be wrong with my car. Since the past two days, the car has been downshifting hard very sporadically. I don't know if it's related, but two (or three) days ago, the car would not start in the morning and I had to jump it. It's been fine since. The battery is about 1 year (or less) old.

I've read that some cars experience this issue when the ECM has gone bad and I'm wondering if that could be it. The car is out of warranty and the dealership wanted $169 just to test it out which almost as much as getting the ECM fixed. I'm wondering if the best course of action is to get the ECM serviced and see if that fixes it.

The car is a 2014 is350 awd with 60,000 miles. The transmission fluid was drained and filled with factory toyota fluid (WS) about 2 months ago.

 

Our transmissions are known to be jerky. My car does that, except I have rough downshifts and up-shifts. Recently, I unplugged the battery and let the ECU relearn the driving habits. This fixed the issue for me.

Whoever did your drain and refill hopefully filled the correct amount back in.

 

Thanks for the reply. It had never been this jerky before. I did the drain and refill. I put the correct amount of fluid back in, then let it warm up, then let it drain via the overflow tube. I'm not a certified mechanic, but I've been DIYing these things for a long time and I think I did it correctly.

 

Is this in normal mode or sport mode?

 

This is in normal mode. I've not tried other modes yet.

 

Known to be jerky? I have noticed an a small issue with my Trans, 15 is350 awd. When shifting from 1 to 2, I feel a small pull, like a hard shift. Eco mode, in gear D (no paddles). So pulling out from a parking or a stop light, at around 12 - 16 mph rpm around 1400 to 1600. Once it shifts from 1st to send, BAM! Small jerk. All else is fine. Any idea? Thanks.

 

Well, I sent the ECU to SIA. They said nothing was wrong with it and they recommended a re-flash. I don't understand what a re-flash would do since I've never messed with it. The problem is still happening. I'm going to take it to Toyota tomorrow since it's a lot closer than Lexus.