2012 3.8 8-speed Auto Transmission Shifting Weird

[Ghettosled]

My 2013 did the same thing. 2-3 and 4-5 almost like it was in neutral before shifting to the next. Problem got steadily worse until it was occurring daily. This was when I had about 60k miles. Build date for the car is January 2013. Hyunday replaced the transmission under warranty, with a $50 deductible. I'm now at 81k miles and the replacement transmission is still performing well.

 

[Rspected]

My 2013 did the same thing. 2-3 and 4-5 almost like it was in neutral before shifting to the next. Problem got steadily worse until it was occurring daily. This was when I had about 60k miles. Build date for the car is January 2013. Hyunday replaced the transmission under warranty, with a $50 deductible. I'm now at 81k miles and the replacement transmission is still performing well.

What I dont get is what they are replacing these transmissions with... 2012 and up all use the same transmission and it's to my knowledge there were never revisions to the units. It is common knowledge that if it was faulty, hyundai replaced it under warranty if within warranty parameters. But wouldnt they just be replacing a faulty unit with the same faulty unit, just the difference being the faults havent surfaced yet?? I would like to get mine replaced with a used unit to finally settle this shifting issue, but I'm not sure what unit to purchase as I dont wanna replace with another faulty one...

 

[Misa3.8]

Hey Guys and Gals, I've got a 2012 3.8 with the 8-speed auto trans. It's got 113k miles on it and I've owned it for about a year (had 107k when I bought it).

I'm having some intermittent but noticeable transmission shifting weirdness. I'm getting occasional bad shifts from 2nd to 3rd and also 4th to 5th.

2 --> 3 : average disengagement of 2nd but grabs 3rd too early while revs are too high (typically only a could hundred RPM drop) and slams into gear. Not overly violent but more of a jerk than a typical shift.
4 --> 5 : slow disengagement of 4th, sits in neutral for around a second, revs climb while in neutral (sometimes as much as 2k RPM increase), slow engagement of 5th. Because of the slow disengagement and re-engagement of both gears I wouldn't call this a slam shift because there's never a big jerk, but power delivery is lost to the wheels for a couple seconds while all this is going on. Strange feeling.

I haven't been able to nail down a consistent set of conditions to reliably replicate the problem but I'd say in general this is happening more when the car is up to full operating temperature. But even then, it's not all the time.

I also did a scan of the computer with an OBD scanner and did receive a code P0955 which comes back as auto shift manual mode circuit fault. However, I have no problems using the manual shift mode, it works fine (though the odd shifting does still happen sometimes in manual mode).

Anyway, I have limited experience troubleshooting automatic transmissions and any insight would be appreciated. Thanks!

P.S. I've purchased "Niteo Motor Medic M3616 Trans Medic Automatic Transmission Treatment & Shift Improver" from Amazon with the intention of adding it to the trans fluid. Figured this couldn't hurt, but please let me know if this is a bad idea. As far as I know the trans fluid has never been changed since Hyundai claims this never needs to be done.

change your tranny filter plus new oil and if that dont work try changing your solenoids , my 2012 3.8 got stuck on 5th gear along with prior bad shifting and it all went away by replacing a couple of solenoids.

 

[Cali Gen]

What I dont get is what they are replacing these transmissions with... 2012 and up all use the same transmission and it's to my knowledge there were never revisions to the units. It is common knowledge that if it was faulty, hyundai replaced it under warranty if within warranty parameters. But wouldnt they just be replacing a faulty unit with the same faulty unit, just the difference being the faults havent surfaced yet?? I would like to get mine replaced with a used unit to finally settle this shifting issue, but I'm not sure what unit to purchase as I dont wanna replace with another faulty one...

where do you live? how far from kansas are you?

 

[Ghettosled]

Food for thought - if I recall correctly from the paperwork, my transmission was replaced with a factory refurbished unit.

 

[Ghettosled]

Giving a personal update - Original transmission replaced at 60k miles. Now at 115k miles (so 55k miles on new trans), the same problem is happening but much worse this time. Problem happens frequently (pretty much every time I drive the car, and just about every time it makes the shift from 2-3 and 4-5), it can take 2, 3 or 4 seconds to make the gear change. It's going to the dealer in 2 weeks. I assume this solenoid is at fault, but hoping to receive a confirmation from the dealer.

 

[Ghettosled]

Back from the dealer. Of course several days before I bring the car in, the transmissions starts to behave. After holding the car for 2 days, they were not able to replicate the problem, so they re-flashed the firmware to see if that helps. Not sure, but the transmission is still normal. Though I don't have high hopes.

 

[RemyBluePearl]

Back from the dealer. Of course several days before I bring the car in, the transmissions starts to behave. After holding the car for 2 days, they were not able to replicate the problem, so they re-flashed the firmware to see if that helps. Not sure, but the transmission is still normal. Though I don't have high hopes.

Happened to me 2012 3.8 Tech Pkg. There is a thread that talked about changing all solenoids and fuel filter with a fresh transmission flush and refill. Did it a year ago and haven’t had this issue return.

 

[shahhere]

Happened to me 2012 3.8 Tech Pkg. There is a thread that talked about changing all solenoids and fuel filter with a fresh transmission flush and refill. Did it a year ago and haven’t had this issue return.

I dont think i have the issue but would it be wise to do a Drain and fill on my 2012 with Tech as it has about 65,000-75,000 miles (not my daily driver so forgot the mileage).

Any suggestions on where to purchase stuff or links to the other threads, thank you in advance!

Shahhere

 

[PauleyDucati]

Hey Guys and Gals, I've got a 2012 3.8 with the 8-speed auto trans. It's got 113k miles on it and I've owned it for about a year (had 107k when I bought it).

I'm having some intermittent but noticeable transmission shifting weirdness. I'm getting occasional bad shifts from 2nd to 3rd and also 4th to 5th.

2 --> 3 : average disengagement of 2nd but grabs 3rd too early while revs are too high (typically only a could hundred RPM drop) and slams into gear. Not overly violent but more of a jerk than a typical shift.
4 --> 5 : slow disengagement of 4th, sits in neutral for around a second, revs climb while in neutral (sometimes as much as 2k RPM increase), slow engagement of 5th. Because of the slow disengagement and re-engagement of both gears I wouldn't call this a slam shift because there's never a big jerk, but power delivery is lost to the wheels for a couple seconds while all this is going on. Strange feeling.

I haven't been able to nail down a consistent set of conditions to reliably replicate the problem but I'd say in general this is happening more when the car is up to full operating temperature. But even then, it's not all the time.

I also did a scan of the computer with an OBD scanner and did receive a code P0955 which comes back as auto shift manual mode circuit fault. However, I have no problems using the manual shift mode, it works fine (though the odd shifting does still happen sometimes in manual mode).

Anyway, I have limited experience troubleshooting automatic transmissions and any insight would be appreciated. Thanks!

P.S. I've purchased "Niteo Motor Medic M3616 Trans Medic Automatic Transmission Treatment & Shift Improver" from Amazon with the intention of adding it to the trans fluid. Figured this couldn't hurt, but please let me know if this is a bad idea. As far as I know the trans fluid has never been changed since Hyundai claims this never needs to be done.

I have a 2012 4.6 liter with the same issue. I bought it with 20k miles. Just started happening about two years ago and it seemingly only happens when outside temp is 50 to 60 degrees F. It doesn't do it in the winter or in the summer. It will do it for a few days and stop for weeks or a month as a few others have said. It is always from 2nd to 3rd and 4th to 5th only. If I accelerate fast it will not act up from 2nd to 3rd but it will still do it from 4th to 5th regardless of how fast I accelerate. It usually just hangs onto the gear and the revs go way up until it finally shifts usually softly but once in a blue moon the Trans will violently shift from 4th to 5th. I was hoping to hang onto this car for along time as I love this car but I might have to start looking for a G90 before she dies

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[G-831357]

My 2012 with 111K miles tranny has slipped since I bought it. Have taken it to 4 dealers. All say same thing, can't duplicate, performs as designed. I am going to deal with it like I have for the past 10 years. Otherwise, I love my Genesis, even though she is starting to look tired Good luck, I actually came on to see if there was a miracle cure yet. Denise

 

[shahhere]

Damm....found this thread that I had replied to and I am not seeing my genny 3.8 tech slip from 2-3 I assume as the car jerks a bit and the rpms shoot up until the shift happens and then its stead. I think its also shifting down hard as I am getting a lurch when slowing down..........

Had the Fluid changed at Hyundai about 1 year ago and about 15k miles are gone ......

Where are the details on changing the selonoid?

Shahhere