AT acting up after long drives
 

I rarely do much extended freeway driving in my BRZ, but I have noticed a couple times when I do that my automatic transmission shifts all wonky when I get off the freeway and hit the surface streets. Instead of nice smooth upshifts, it clunks jerkily. And instead of rev-matching on downshifts, it almost feels like it's doing the opposite and under-revving while it shifts. Has anyone had this experience? Is my transmission overheating maybe? This happened after a long freeway/traffic drive a couple of days ago but since then all has been normal and happy again.

For reference, I'm driving a 2015 BRZ with 6AT and just hit 2,000 miles. Only performance mod is UEL headers and an EcuTek tune.

(I did try to search to the site for this issue, but couldn't find anything.)

What mileage are you at?

When my wife's Malibu was shifting whackily (way worse than what your BRZ was doing, b/c her car was slipping out of gear), it was b/c she hadn't changed her AT fluid in forever. Then again, she was at 120k miles, and had never changed the AT fluid.

Im not a mind reader but I think 2000 miles

Possible, but could be more. Figured it was low, but with some folks you never know.

Yep, miles are low enough that I'm not terribly worried about the transmission fluid. I'm just wondering if anyone else has experienced this and if it's an easy fix?

I also have an automatic, and this is caused by the transmissions adaptive shift control, (not the right name). It learns the way you drive and shifts accordingly. So, long highway drives give it the wrong impression of the way you want to drive. It settles down with more miles, but nobody wants to wait till then, so I used to just put it into sport mode for a couple miles when I left the freeway, then when I turned off sport mode it was back to normal.

P.S. It also picks the worst RPMs to shift at, right betwen 3000 and 4000 RPM in the middle of the flat spot.

Yes, that's totally what it does! It even affects how it shifts while I'm in manual mode (which I use 90% of the time--EXCEPT while I'm on a long freeway drive.) As long as I know why it's happening, then I can deal with it. I just want to make sure it's not something wrong that I need to get fixed. Thanks!