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

[maslin]

Originally Posted by Arrex

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

"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

A bulletin is just guidance for a known problem. It applies only to the vehicle specified for the problem specified.

A software update is just that, a software update. Usually the first step in any transmission complaint, flash up the newest software. Along with check the fluid level and verify the complaint.

[Dadhawk]

Originally Posted by maslin

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

This is the one for the '13.

http://www.ft86club.com/forums/attac...6&d=1386706237

Occurs in idle with the AC off.

Some Scion FR-S vehicles may exhibit an engine RPM drop while idling with the A/C off. The Engine
Control Module/ECM (SAE term: Powertrain Control Module/PCM) logic has been revised to address
this condition. Use the following repair procedure for ECM (PCM) reprogramming.

[maslin]

Idling with the AC off isn't slamming gears while coming to stop. I just can't connect the two.

Torque converter stuck on while you're coming to a stop feels like lugging a manual car. Torque converter stuck on during shifts often feels like a nasty shudder.

Our vans have an issue where the torque converter can't dump pressure fast enough when shifting, and just before you stop. It feels like you hit the rumble strip. We replace the valve body and relearn the torque converter, there's a fix online to drill a hole in one of the valve body end plates to allow pressure to bleed off faster.

I may or may not have have done it before, and it may or may have worked.

A dip in RPM will give that nice shake though the car while it fights to idle, but it's not the same as when the torque converter is sticking.

[RZNT4R]

This is a long shot, but consider this:

Get a can of carb cleaner and clean your maf and throttle bore (ideally take both out, and clean the throttle with a cleaner-soaked rag rather than spraying it directly). It might seem unrelated, but at 55k miles you're probably got some accumulated dust on the maf and oil soaked carbon in the throttle bore.

The transmission tries to adapt to the engine load, and the maf is usually the main signal for that, it doesn't have to be way off, but a dirty maf's error will be worse near idle and send a slightly wrong load signal to the transmission, which is where you're having your problem. Same with a dirty throttle, cars used to have idle control solenoids or stepper motors that would control an air bypass around the throttle to control idle speed, now that is done by the throttle plate closing further than it's neutral closed position into a finely machined section of the bore. Even if the engine computer can adapt to the carbon and correct it's idle speed to a certain point, it can cause the engine to behave strangely as the throttle plate hunts around the carbon "steps" to get the desired idle.

As I said, it's a long shot, but you're in it for the cost of a can of carb cleaner and 30 minutes.

[Arrex]

Originally Posted by Dadhawk

This is the one for the '13.

http://www.ft86club.com/forums/attac...6&d=1386706237

Occurs in idle with the AC off.

I think this is what the dealer did on my car when they said they have updated the software (indicated on the invoice as Intermittent RPM drop condition EG1316 0.40) However I do not see an Authorized Modifications Label under the hood suggested by S-SB-0040-13.

Went to another dealer inquiring about this, they plugged the computer in and told me my vehicle software are all up to date.

[maslin]

Originally Posted by Arrex

I think this is what the dealer did on my car when they said they have updated the software (indicated on the invoice as Intermittent RPM drop condition EG1316 0.40) However I do not see an Authorized Modifications Label under the hood suggested by S-SB-0040-13.

Went to another dealer inquiring about this, they plugged the computer in and told me my vehicle software are all up to date.

Mercedes labels are only for CA.

[Arrex]

Originally Posted by maslin

Idling with the AC off isn't slamming gears while coming to stop. I just can't connect the two.

Torque converter stuck on while you're coming to a stop feels like lugging a manual car. Torque converter stuck on during shifts often feels like a nasty shudder.

Our vans have an issue where the torque converter can't dump pressure fast enough when shifting, and just before you stop. It feels like you hit the rumble strip. We replace the valve body and relearn the torque converter, there's a fix online to drill a hole in one of the valve body end plates to allow pressure to bleed off faster.

I may or may not have have done it before, and it may or may have worked.

A dip in RPM will give that nice shake though the car while it fights to idle, but it's not the same as when the torque converter is sticking.

Appreciate your analysis and now I am even more confident on what one of the shop told me was correct: torque converter behavior is whacked

[Arrex]

Originally Posted by RZNT4R

This is a long shot, but consider this:

Get a can of carb cleaner and clean your maf and throttle bore (ideally take both out, and clean the throttle with a cleaner-soaked rag rather than spraying it directly). It might seem unrelated, but at 55k miles you're probably got some accumulated dust on the maf and oil soaked carbon in the throttle bore.

The transmission tries to adapt to the engine load, and the maf is usually the main signal for that, it doesn't have to be way off, but a dirty maf's error will be worse near idle and send a slightly wrong load signal to the transmission, which is where you're having your problem. Same with a dirty throttle, cars used to have idle control solenoids or stepper motors that would control an air bypass around the throttle to control idle speed, now that is done by the throttle plate closing further than it's neutral closed position into a finely machined section of the bore. Even if the engine computer can adapt to the carbon and correct it's idle speed to a certain point, it can cause the engine to behave strangely as the throttle plate hunts around the carbon "steps" to get the desired idle.

As I said, it's a long shot, but you're in it for the cost of a can of carb cleaner and 30 minutes.

Forgive me but, is throttle bore the same as throttle body? I have my throttle body cleaned on a regular basis, and actually as recently as end of April 2019. As for the MAF, I will definitely look into it, thank you for the insights!

[OwlDance]

Originally Posted by Arrex

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.

No vibrations on my end, just the jerk when coming to a stop. I do notice a bit of stiffness at times when shifting in manual mode, but I can't put my finger on the parameters that cause it. Sometimes it's smooth, sometimes it's a small bump (engine warmed up, transmission warmed up, etc.)

However I did read in the development article of the car (it's on the forums here somewhere) that supposedly shifter feel was deliberate on the AT, according to the AT development team. It sounds odd to me as I feel like any sensation presented in AT-MT mode would just be a sign of inefficiency or more drivetrain stress. Wouldn't smooth shifts be better all around? /shrug

[Arrex]

Originally Posted by OwlDance

No vibrations on my end, just the jerk when coming to a stop. I do notice a bit of stiffness at times when shifting in manual mode, but I can't put my finger on the parameters that cause it. Sometimes it's smooth, sometimes it's a small bump (engine warmed up, transmission warmed up, etc.)

However I did read in the development article of the car (it's on the forums here somewhere) that supposedly shifter feel was deliberate on the AT, according to the AT development team. It sounds odd to me as I feel like any sensation presented in AT-MT mode would just be a sign of inefficiency or more drivetrain stress. Wouldn't smooth shifts be better all around? /shrug

I have an update on the hard upshifts in my original post, but the jerking & vibration as I come to a stop are still there unfortunately.

I have a feeling at this point Totoyta will use any opportunity to say these symptoms are "normal" because they don't have any idea what's causing it and / or so they don't have to fix it for us.

Best wishes to you though hope your car doesn't get worse!

[Celigts]

Simple fix ... costly but should have been done from the factory ...

Buy a manual transmission... ����

[navanodd]

I'm also having this issue, and I also only started noticing it after a ATF change. I think it had more to do with the ECU relearn process than the actual fluid change.

I've done a quick cleaning on my throttle body, which seemed to fix it temporarily (again, I think related to ECU relearn from disconnecting battery). I plan on cleaning the MAF next.

I've actually had 2 stalls now when coming to a stop.

[James H]

I believe the auto boxes in the Lexus IS are the same as the ones in the BRZ. I experienced the same thing when driving my brother's IS350. Shifts are smooth in auto mode but very rough in manual. It jolts you when coming to a stop, almost like someone who can't drive manual well. It gets to the point where you don't want to use the paddle shifters anymore.

[Arrex]

Originally Posted by navanodd

I'm also having this issue, and I also only started noticing it after a ATF change. I think it had more to do with the ECU relearn process than the actual fluid change.

I've done a quick cleaning on my throttle body, which seemed to fix it temporarily (again, I think related to ECU relearn from disconnecting battery). I plan on cleaning the MAF next.

I've actually had 2 stalls now when coming to a stop.

Interesting, for me it's the other way around: car was jerking + shifting hard all of a sudden; got the tranny fluid changed and it was fixed for a couple days. Hope you get some results from cleaning the MAF