Automatic Transmission issue- dealer is not recognizing the issue, please help!
 

***Update 11-May-2019***
Per RZNT4R's suggestion (thanks!) I cleaned the MAF sensor. 50 miles so far after cleaning it the upshifts have gotten significantly smoother.

Also, after cleaning the sensor, despite my vehicle being a 2013 I was able to get another dealer to have S-SB-0021-15 done, as many have indicated their issues have been fixed after the TSB (http://www.ft86club.com/forums/showthread.php?t=96615). However the jerking and vibration showed no signs of improvement / fix.


***Original Post***
Hi all,

I have a 2013 FRS with an automatic transmission. In early March I begin to notice hard shifts, and my car would jerk forward and vibrate as I come to a stop (the jerk feels like as if I pressed on the brake hard all of a sudden, but it's the car doing this by itself). While it does that the RPM would dip for about 100-200, then come right back up as the car comes to a full stop.

The dealer has done 2 separate works on my vehicle because of this issue:
1. Transmission fluid flush
2. Transmission pan gasket seal and software update

Right after both times the symptoms described above went away for a few days, but came back worse than before.

Three different Toyota dealers have looked at it and say this is "normal vehicle behavior". What I don't understand is: how come the car didn't use to do this, and how come after the fluid flushes the symptoms would temporarily go away? How is this normal??

I took it to three independent shops as well to get another opinion, one said this was due to my high pressure fuel pump having a low pressure, one came up with 2 codes (U0101 & U1201) but the dealer checked after saying these are not current codes, and the last shop said the following:

"Torque converter is staying locked longer than it should be. However the torque converter is doing what it is being commanded to do. When watching the data while driving, the torque converter clutch solenoid does not shut of until right as the car stops. Then on upshifts it is being commanded before the completion of the shift into certain gears. This causes the firmer shift feel. I reset the transmission adaptions, but it is likely to go back to where it was . Seems to be a very common issue with the automatic transmission on this car, not sure there is anything that can be done that will be permanent"

They suggested it's likely a software issue with the ECU / TCU, but cannot guarantee, all they found were the weird behaviors of the torque converter / solenoid

Even after sharing this detail with the dealer, they still say my car is normal and this is not an issue / nothing they can do...

I am really worried I will be wearing out the torque converter & the entire transmission prematurely. Is anyone else having similar issue? Any guidance and insights would be much appreciated. Thanks all!

P.S.
-During this whole time there were no CEL or any faulty lights
-My car is all stock except the wheels/tires
-55400 miles, bought the car new in 2012

2019 AT here, 8500 miles in, my car's pretty much done this from the start but it's only noticeable in manual mode (can't speak to sport mode, it's not great so I don't use it).

Best way I can describe it is that I get that sudden "bump forward" when coming to a stop as the RPMs drop to the downshift range (IE, ~1050 RPM). It's only really noticeable from gear 2 --> 1 at this time.

It basically feels like the torque converter locking up momentarily before letting go again when coming to a near (or total) stop when it downshifts from 2 --> 1. Does that sound about right?

I don't remember if this happens in non-manual, non sport mode, I tend to switch back and forth between it and MT on the fly, depending on the driving situation.

Edit: For the record I think this is roughly normal.

Sounds like a torque converter issue to me as well. Whether it's the actual torque converter, a solenoid, or control unit... I have no idea.

Is there a process to relearn the torque converter? You said they reset the adaptations, but that doesn't mean it was taught in afterward. Try driving up to speed, then coasting to stop through all the downshifts. If it won't come to an actual stop, brake very lightly to stop.

Try that a few times and see if it improves.

What you described sounds exactly like what mine is doing. Do you feel a vibration coming from the car just as the car comes to a near/full stop as well?

Interesting things is: before I would ONLY notice the jerk/bump forward in manual mode when going from 2 --> 1 as well, but now even leaving it in automatic (both sport or non-sport mode) the car does that VERY NOTICEABLY.

I am troubled by the fact Toyota saying this is normal and every car does it, when other FRS / BRZ I test drove recently (and my own car before March) weren't exhibiting these symptoms in automatic mode.

I'd say normal based on 5 years on ownership with an auto, it'll happen in manual mode.

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

I have driven about 45 miles after they reset the adaptations, but so far it's still doing the same symptoms.

I have not let it coast to a stop through the downshifts (without braking / with minimal braking) however I will give it a try later today and see if anything changes

You sure it's being caused by the AT? There was an issue with some 2013s with the engine mapping causing the RPM to go too low in idle. I've experienced only once or twice but it is low enough I've seen the DRL turn off in the reflection in the car in front of me.

I've found the parameters in which a transmission can "learn" to be very very small. Without the computer attached you would almost never shift at the correct rpm's or load in the real world.

While a correctly adapted transmission will learn your driving style, an incorrectly/reset adaptation will rarely work itself out. Many cars do not perform the 2-1 downshift until you are stopped, you shouldn't feel it, but under certain conditions you may.

Probably a dealer/serious indy shop type of thing. If it wasn't doing it before and you're willing to pay to fix it, there's almost always a solution. You have to decide how much $$$ it bothers you.

Here you go...forgot this TSB was a thing.

http://www.ft86club.com/forums/showthread.php?t=96615

http://www.ft86club.com/forums/attac...1&d=1443640063

"Some 2015 – 2016 model year FR-S vehicles may exhibit a condition where the engine idle speed fluctuates (typically 500 – 1000 RPM) only when the transmission is in the Park or Neutral shift position. "

OPs car is a 2013. DTB doesn't apply to his car, and not the same complaint.

The second time dealer did work on my car they indicated an "update":

"Intermittent RPM drop condition EG1316 0.40, Test drove Vehicle and was able to confirm customer concern. Recommend to reseal transmission and perform update. Work Complete"

When I asked they said it was a software update, not too sure if it was the TSB

The dealer (3 different Toyota dealers in the DFW area) have indicated nothing is out of the normal when they did they diagnosis, so I assume to them there was no engine mapping issue either.

2 of the independent shops I gone to told me this is related to the transmission, while one said it was about my high pressure fuel pump not giving enough fuel into the engine.

Although I cannot say for certain, not being a technician / mechanic myself, but I am leaning towards it's the AT /torque converter/solenoid issue per the 3rd shop's suggestion

Eh, read through the thread, it's a commonly reported "issue" with some reporting the TSB helped them, even cars before 2015.

Agreed. Right now I can't even get an idea how much it will cost as the dealer is saying "there's nothing to be fixed". Indy shops that I have gone to (the 3 mentioned in my original post) said if this is a software thing only dealers can mess with it. So I am pretty lost on how to proceed even if I am willing to dump some cash on it