Transmission Shifting Issue

I have this exact problem with my 2017 SE almost 60k on the dash. I’ve had the vehicle nearly two year and it started towards the end of this past winter. Initially, it would only have the hard shift after a cold shift and only the first time it shifted from 1st to second. After that, normal shifts. It didn’t do it every morning but it would only do it in the morning.

Then about a month ago, my wife had just got home from a 39 mile drive and I took it to get gas. It hard shifted from 1st to 2nd every time I came to a stop on my way to the store. After getting gas and starting it back up I headed to the store and there were zero hard shifts. A few days later, same type of situation, it had just been driven for 30 or so miles. I then took it to the store and it had shifted 1st to 2nd on the way there. Smooth shifting on the way home.
I have found zero results on my research of this problem. I can not afford to take it to a shop to get it checked. There are no dash lights on and my home obd2 scanner isn’t finding any error or pending codes so I’m at a loss. It’s a sealed transmission so all I can think of is a hard failure or some sort of electric solenoid (maybe there is a computer problem at start that causes the initial hard shift or continuing hard shifts until the vehicle is restarted). The next time it happens I plan on pulling over immediately and restarting the vehicle to see if the issue continues.

Please update if you find anything out, and I will do the same.

Same transmission slipping issue

I have a 2017 Santa Fe AWD and the 3.3L engine, 65K miles. I bought the car used almost two years ago. Within the last two weeks I started to feel a slippage after backing out of my driveway as I shifted into drive. It would slip and you'd hear a load clunk. Drove to the end of the street and it would make the same noise and feel turning onto another side street. If I placed the car into manual mode I could shift without hearing or feeling the clunk noise. Took it to Chapman Hyundai dealer here in the Phx area. They told me I needed a new transmission and quoted me $3800 with a 1 year/12K mile warranty. Took it to a local transmission shop who told me that a gear had come loose inside and that they couldn't rebuild and I needed a re-manufactured tranny. $4000 later (2 for the tranny, 2 for labor) I get the car back and it is still doing the exact same thing. Its going back to the trannny place on Monday, I just don't understand what else could be wrong.

Same issue here. Started with a hard shift from 1 to 2 when it was cold, every once and a while. Then one day, every stop was a hard shift from 1 to 2. This would happen periodically and shutting the car off and turning it back on would solve the problem, until next time. I called Hyundai several times about it and they said that they have to see it. BUT, I could never get anyone on the phone at my local dealership when it was having the problem and reception was telling me everyone was too busy to see me. It was so frustrating that I wrote a letter to corporate. Corporate called me several times, I didn't pick up originally because I thought it was a spam call. They told me they spoke directly to the service manager at my dealership and they were ready and waiting for me to show the issue to them. It took months before the timing was right, as it always seemed to happen after the service center was closed. Finally, a few days ago it was happening in the middle of the day. I headed to the dealership and it quit 2 stop lights before I arrived. It was SO frustrating! So, I drove another 4 miles or so ,stopping and shutting the car off and starting again every 1/4 mile. Eventually, it started doing it again and I hurried back to the dealership. They were attentive and on top of it. Their mechanic came out and got in the car with me. It did the hard shift and he immediately said, "looks like you need a new transmission." He said it could be a temperature sensor, but seems like a news trans is in order. They got me setup with a rental and are working on it now. Like someone else on here said, they have to experience it for themselves. If they're not open to you popping in and showing them, contact corporate. Best of luck everyone!

I started having this exact issue with my 2017 Santa Fe Limited Ultimate after the dealership did a transmission fluid flush in April. It began slowly - and two weeks ago it began slamming hard into second gear and then progressed quickly to slamming hard into the downshifting gears. Parked it and waited two weeks for my appointment with the dealership to fix it. They couldn't recreate the issue and the Technician did an adaptive value reset on the transmission and brought the transmission fluid "up to the proper level." This fix, driving the car home, seemed to make the problem much worse and we have to take it back to the dealership tomorrow morning. They said there were no codes showing and the car is otherwise fine. I bought this used in 2019 with 32k on it and it now has just over 80k. I've had all maintenance completed and bought the extended warranty at purchase as it was a Certified used purchase. We'll see what they say tomorrow. I LOVE this car - everything about it is perfect for me except for this new issue.

Update on my transmission issue from hell journey with Hyundai. Dropped the car off on the 16th and was unable to reach anyone for a week to find out what was going on. Got a template text message that the "tech was still working to determine the problem and they would contact me when they knew more and thank you for your patience" crap. So frustrating.

Finally spoke to a service manager on Thursday the 29th who said the techs haven't been able to "reproduce the problem" even though this service manager rode with my husband when we brought the car back and it was acting up like crazy for him and the service manager was in the car at the time. I consider that proof more than sufficient for "documentation of the problem."

I told the service manager to take the car home with him and drive it like it was his. It's under warranty and it's astonishing to me that, if you're paying cash, they'll replace a transmission with NO PROBLEM. If you try to get a transmission replaced under warranty they will find every excuse under the sun to not do it. The service manager even asked me if I accelerate hard off stop lights or braked hard when needing to stop - as if this problem is a driver's fault.

We'll see what happens this week...