Hi, I have a 2019 Tucson Ultimate that I'm having an issue with. On two separate occasions (December 2019 and April 2020) I encountered the following: I've been driving on the highway around 75mph(ish) and my forward collision warning light comes on. Within a minute I heard a very loud clunk and I rapidly decelerated to around 50mph. At the same time, my RPM's shot up to around 4500 and would not go down. I pulled over, turned of the car, waited a couple minutes and turned it back on...everything is back to normal. No one around me, no snow or other debris and nothing on the radar screen in the grill. Outside temp around 30 in December and 60ish in April.

The first time it happened, I took it to the dealer and they weren't able to replicate it so nothing was done. I have not taken it back this time (yet) but was wondering if anyone else has encountered anything similar?

 

Did anybody attempt to determine the cause of the clunk you heard ? That is not normal and should be checked out thoroughly . Until that is found ,It just might happen again.
Whatever took place affected the electronic throttle control and that should have placed a code in the system. When you turned the engine off it apparently allowed a reset and that is why it ran ok after you restarted it The RPM problem is NOT supposed to happen because there are supposed to be safeguards in the design to prevent that.

It is not my intention to alarm you, but there could be some type problem with the ADAS (Advanced Driver Assistance System).
I would think your dealership personnel have the training and equipment to troubleshoot this and would insist they check that system carefully and thoroughly.
Also suggest you familiarize yourself with that section in your owners manual so you can better describe what is going on.when you take it back to the dealer.

Let us know how you make out with this, thanks.

 

Will do and thank you for the reply. I called my local dealer and I'll be dropping it off to them this week. I'll update the post once a diagnosis is made.

**Tucson has been at the dealership since 4/20 with no updates from the dealer. Stopped by on Saturday and their service dept. was closed. Was told I would receive a call from the manager on Monday...nothing but crickets.

 

Finally got a call back from the service manager and he said what I experienced was due to the Adaptive Learning. I called BS and said dropping from 70-75 to 50mph on the highway was not adaptive learning; it was an issue with the ADAS. He actually said you're wrong, it is. They refused to do anything with the vehicle because he couldn't duplicate the error and he said there was no code in the system. He said it would need to happen again for them to be able to justify replacing anything under warranty. I told him I wanted to make sure I was clear that the dealerships direction is to let it happen again and hope I don't have someone behind me next time and suffer a rear end collision? One word response..."yes".

I'll be sending a message to Hyundai Corporate and rest assured will never purchase another vehicle from Superior Hyundai in Beavercreek, Ohio again. Now I'm off to do some research on what new vehicle to buy so I can dump this thing.

 

This is most unfortunate, Would you be so kind to update us as to what corporate says?
I realize you didn't ask for my opinion, but sometimes we can get a more positive response by consulting with another Hyundai Dealership Service Dept..
Have you considered that move, especially if you are happy with your vehicle otherwise?

 

More than happy to provide any response I receive and yes, I plan to take it to another Hyundai dealer in Dayton. Hopefully they'll be more willing to take this safety issue seriously.

 

Received what appears to be a canned response from Hyundai Corp..."your satisfaction and safety is our number 1 priority...." blah, blah.

The same issue occurred again while on the highway with my two daughters so this time I didn't stop or turn off the engine. I drove straight to the new dealership and presented the truck to them still running. Their service manager took it out for a trip around the block and immediately said they'd give me a loaner and that it wasn't safe to drive. (This was 6 days ago). They were able to pull multiple trouble codes:

42700R00 Switch Assy-Inhibitor Transmission Range
P1118 Throttle motor – malfunction
P1155 Electronic throttle system (ETS) – malfunction
P1529 Transmission control module (TCM) – communication

They also said they were going to replace a rain sensor...not sure if it was related, but since most of the modules talk to one another, better safe than sorry.

I received my vehicle back a couple days ago with all repairs done under warranty. I'll keep this post updated if any future issues come up. Still not happy with the original dealership I took it to and I blasted them on the electronic survey I received; I don't like doing that but after the poor service and lack of general give-a-crap, I felt it was warranted.

 

You did the right thing by not shutting the vehicle off and bringing it directly to the dealership.
The big clunk is a mystery.
Thank you for the update.
Glad you are having it taken care of.