AT Transmission Hard Shifting
 

Sorry in advance for the long post. I've been a long time lurker and love all the information on here, I'm hoping some of you may be able to shed some light on my transmission issues.


I bought my auto 2015 FR-S in late May. At about 1K miles, I noticed that occasionally when I was in sport mode (Edit: or manual mode), I would get hard, notchy shifting, particularly going into 2nd or 3rd gear. The most interesting thing, is that if I'm getting the hard shifting, and I pull over, turn the car off, and turn it back on, it starts shifting smoothly again. Exactly as described in this previous post:


http://www.ft86club.com/forums/showthread.php?t=80500


I tried everything I could to consistently recreate the problem to no avail. It happens probably every 3 times I drive the car. Sometimes it will happen when I put it into sport mode(Edit: or Manual Mode) with a cold engine in the morning, and sometimes it will happen after I've been going 80MPH on the highway for half an hour. Seems totally random. I tried all the obvious things like making sure I wasn't letting off the gas during acceleration or doing anything weird. I tried resetting my computer as well by disconnecting the battery for 20 mins.


If it is happening in normal auto mode, it's much more subtle.


I took it into Toyota a couple weeks ago, and was unable to recreate the problem for their tech since I turned the car off. They said that next time it happens and you're in the area, stop by and keep the car on so I can show them the issue. Sure enough, 1 week later I was in and the tech agreed right away that something was wrong. Multiple techs and service managers drove it that night and they all agreed that something wasn't right.


So I left my car there last Tuesday night and just picked it up last night (Monday). They took OBD data, sent it to Toyota, and their response was to check the transmission fluid and reset the computer. They were unable to recreate the hard shifting during the four days and putting close to 80 miles on the car. They ended up adding half a quart of transmission fluid. They still couldn't recreate the problem so they gave it back to me and told me to drive it and see if it comes back. Sure enough, as soon as I pulled out of my work parking lot today, the hard shifting was back.


I did some datalogging comparisons with and without the hard shifting with my Bluetooth OBD reader and have it all in excel if anyone wants to PM me and take a look at it (I'm an engineer who loves data). I wasn't able to really see anything. I also took videos of it happening:



***Watch the tachometer, you can see it stumble going into second gear.

[ame="https://www.youtube.com/watch?v=0cZIyrmjJZs"]Hard Shift Sport Mode - YouTube[/ame]


[ame="https://www.youtube.com/watch?v=OClb8zUFu9A"]Normal Shift Sport Mode - YouTube[/ame]


Sorry for the bad quality, youtube wouldn't let me have them in HD.


So here I am. Anyone have any experience with this or ideas on what might be going on? I'm pretty frustrated and don't want to have to drive a rental for another week while they putz around figuring out what's wrong.


Thanks in advance!

I've had a 14 auto since November of 2013 and have seen this issue but never really looked into it besides subbing to the various forum threads. Like you, I can never recreate the issue consistently but I've always noticed it when switching from auto to manual and shifting. It essentially feels like a hard shift and you can feel the car lurch forward almost

@Bergen23

Looks like a DSG!!! Badass!!!! How can I recreate this

Interesting... never had this issue. Mostly use sport mode when I'm driving extremely hard on twisties however.

2015 FRS, approaching 5k miles, bought in June.

It looks like a timing issue. Perhaps a limp mode?

Normal shifting looks coordinated with throttle applicatiion as soon as the higher-gear clutch/band/whatever engages.

The abnormal seems like there's undershoot and delay of throttle application. Does that seem ballpark?

This happens to me quite frequently. I had my EGI ECU replaced and that didn't fix it. Starting to lose hope now that there's a fix for it.

happened to me often, and most of the time its when its at a cold start and in sports mode with manual mode on. But it usual stops whenever sports mode is off. Got my car dec 2014, 2015 frs

im currently at 6k

I think its the undershoot / delay situation too.


It's like when you drive a manual tranny car and don't feed in some gas as you let the clutch out in the higher gear--- the car will jerk backward a bit because the engine is braking the car rather than accelerating it.

I have noticed this in sports mode too at times. I figured it was just sports mode doing its thing, but just as you only happens sometimes in sports mode, not always (but I have noticed that shifts in general are harder in sports mode compare to reg mode)

Wouldn't this throw a code though?

When I pulled out of my driveway this morning, I put it right into sport mode and wasn't getting the hard shifting. I turned sport mode off and on and a few times and couldn't get it to happen. I then jumped on the highway in regular auto mode for 20 mins. I put it into sport mode when I got off the highway and the hard shifting was suddenly present. Going to try this again tonight and see if there is a pattern.

I've been trying to find out what makes it happen. Sometimes it starts when my tpms light comes on. Sometimes it starts after using cruise control, some times it starts after going 80-100kmh for any time and sometimes it just happens with nothing I've "done" so to speak, except for driving in M mode.

Edit: but like someone else mentioned. If I turn the car off for even a second, it goes away, although it does come back quickly.