2012 Hyundai Sonata hybrid has been experiencing rough transmission operation after software update service was completed for the car at a dealership. The software update to the car computer system was know as "service campaign 953" (knock sensor detection system - engine monitoring technology). Ever since the car computer system was updated, the transmission has been operating very rough. The car started jerking when in motion and the engine would race when I stepped on the accelerator. Also, the service light on dashboard illuminates. When L called the dealership and reported the transmission hesitation problem, they tried to fix the issue by running diagnostic tests and replacing the ESC relay. All did not solve the problem. Later, L was told there was nothing they can do about about it, unless am ready to take care of the expenses (diagnosis and mechanical), because the car is out of warranty due to mileage. I told them the car transmission was operating smoothly until after the software update was applied to the car computer system. As of right now, I believe the software service to the car has caused this changes in the transmission. I also think, the dealership should have worked on fixing the issues on my car regarding the software service update. I want to this issue to be critically looked into, since there may be many out there with Hyundai Sonata transmission predicament.

- Lithia Springs, GA, USA

My 2012 hybrid Sonata, 104,000 miles, suddenly started jerking and nearly stalling one recent morning on a drive from home on a divided road. It barely moved forward, badly jerking, message on the screen was : hybrid battery low. Pull up safely an place the car in park". so after 1/2 mile, I returned home. Because of low speed on a divided road, there was a serious concern of being hit by another car. I had the car towed next morning to the Hyundai dealer. They reported 'nothing wrong found' and returned the car which is running fine, though jerking transmission at low speed. I am wondering if this happened away from home, what shall I do. I need assurance that that will not happen again. How do we get that assurance ?

- Berwyn, PA, USA

I own a 2012 hyundia Sonata SE with 136,000 miles. This car has a long list of issues from purchase date of 2011 to right now. The engine/transmission has been jerking, stalling and not having full power intermittiently as of the three years but this surpasses it all. July 2, 2019. I was leaving from a parking lot in reverse and heard a loud boom noise, I thought a collision occured. I looked all around and nothing was there. So, I place the gear into drive.....boom again. My entire body shook and the car proceed to jerk and hesistate through the parking lot. Nervously, I had to get on to the dangerous interstate 35 South and the car struggled to get the optimal entrance speed onto the freeway. It jerked more and more while on there and immediately exited at the first exit. The RPM dial was extremely higher than normal. I had to take side roads to avoid being hit or hitting someone to my house. I have been slightly terrified driving this car before with the stop and go jerking combined with randomly not starting, but now I'm beyond that now. Driving the last couple days has me a nervous wreck with the reading of this issue happening nationwide with our kids in tow. Please NHTSA, make hyundia accountable with these documented unsafe cars on our roads all over the country. This is not right. Thank you

- Richardson, TX, USA

Engine failure: I own a 2012 Hyundai Sonata. On July 2, 2019, I was driving home from work on the highway in the far left lane, driving approximately 60 miles an hour when suddenly the engine stalled and the car would no longer accelerate. It then started making a knocking noise. This was a very scary occurrence especially to happen on the highway. But fortunately, I was able to slowly cross over, safely get off at the nearest exit, and pull over to the side of the road. Several warning indicator lights were flashing on the car (including the engine light) and I detected a slight burning odor (but no fire). I was able to restart the vehicle but it stalled again and eventually was towed to an independent mechanic who diagnosed a complete engine failure. The vehicle wasn't repaired but towed to the closest official Hyundai dealership (256 North franklin St, hempstead, NY) for assistance. The following recalls are associated with my vehicle: Recall# 17V226000 (engine), and #15V568000 (engine). At the time of occurrence the vehicle had oil in the tank and had approximately 88,000 miles on it which should not have affected the engine at all. I sincerely hope that by reporting this incident, it will assist the Hyundai dealership in repairing or replacing the engine in my vehicle as stated in the recall and thereby preventing this from ever happening again. This is a very dangerous incident and wouldn't want to ever subject myself or my family (who also ride in this vehicle) to a terrible incident such as this or worse.

- East Meadow, NY, USA

We had engine recall for last 2 years. Had all recalls taken care of including the dealer listening to engine & 2 weeks ago installing a sensor. This sensor supposed to if needed set off check engine lights & reduce power to 50% so you can safely get to a dealer. My daughter was driving on a major highway when engine lights came on & she lost all power and car stalled in middle of a merge lane. No warning or reduction in power, stalled where it stopped. I came & parked behind her with my 2017 tuscon waiting for a tow truck. This sensor recall did not work for us & put my daughter in real danger & gave me a false sense of security in this recall. I want nothing but for no one to get hurt. Please fix this issue, its not helping its going to make it worse. Waiting for new engine, dealer says on back order

- Coram, NY, USA

My steering is cluncking when I turn my wheel. I brought my car in for 2 recalls and I assumed this would be on the recall list as well. The hyundia dealership that I brought the car to said that this was under warranty but I have exceded the manufacutrers warranty to cover this and it would cost me almost $300 to fix it myself. I know this is a common problem for this vehicle since my son is a mechanic and has told me of several that they have replaced. I would hope that Hyundai would fix the problem for me since I have had this car for 7 years and no compalints. If they don't want to fix this problem I will just trade the vehicle in for a manufacturer that will take care of problems when they happen.

- Myrlte Beach, SC, USA

The contact owns a 2012 Hyundai Sonata. While driving 20 to 40 mph, the vehicle jerked violently and the check engine indicator illuminated. The contact attempted to place the vehicle in reverse and depressed the accelerator pedal, but the vehicle failed to accelerate. The contact also noticed an abnormal odor coming from the hood and base of the vehicle. The dealer was not contacted. The vehicle was not diagnosed or repaired and the failure recurred. The manufacturer was not made aware of the failure. The failure mileage was 130,000. The VIN was unknown.

- Easley, SC, USA

The contact owns a 2012 Hyundai Sonata. When the vehicle was placed in park and turned off, an alarm sounded that alerted the contact to place the vehicle in park. As a result, the vehicle would not shut off. The vehicle was not diagnosed or repaired. The dealer and manufacturer were not made aware of the failure. The failure mileage was 123,000.

- Freeport, NY, USA

While on the freeway, the car was making hard shifts when accelerating and decelerating. Then it slowed and gas pedal when pressed was like being in neutral, then it would catch and stop again...then had no power at all. Extremely dangerous. Was able to pull over after nearly causing an accident and was towed to the dealer

- Moorpark, CA, USA

At any speed the engine will return to idle without moving the gas pedal. It will do the same thing when using cruise. Pushing the gas pedal will re-engage the engine. It acts as if you take your foot off the gas. There are no warning lights and everything acts normal (lights, power steering etc). This started in mid March 2019. It is becoming a daily issue.. my wife is scared to drive it. I took it to my Hyundai dealer and they could find nothing wrong. It did not do it for them. They said it showed no codes. I keep very good care of my Sonata. It has 180,000. My dealer is noller Hyundai topeka ks.

- Rossville, KS, USA

2012 Sonata inconsistently will display "shift to P" when trying to turn the vehicle off. The car is always in park when this happens and it won't allow the navigation screen to turn off. The engine will turn off but the battery will drain due to the screen being constantly illuminated during this issue. Sometimes it can take up to 25 minutes to get this issue to resolve itself by restarting the engine, shifting to drive and then back to park, and then attempting to turn off the car over and over again. This issue occurs more often when going on short drives.

- Huntley, IL, USA

While driving in traffic car began to jerk and lose speed though the engine was running. The car stopped in the middle of moving traffic. Transmission fluid spilled out profusely. Transmission was replaced but started to slip again the same day I picked it up after new (remanufactured) transmission was installed by the Hyundai dealer. Prior to this transmission issue, the alternator in my car failed while driving in the middle of moving traffic. This complete transmission failure occurred shortly after a new engine was installed because the original engine seized and failed prior. Alternator was replaced. The newly installed alternator failed again. A new alternator was once again installed. I am now having similar electrical problems yet again and there is a current concern that the vehicle may possibly stop suddenly and hazardously again while in motion.

- Baltimore, MD, USA

The car will turn off while driving. We tested the battery and the alternator and everything else that will be the issue but everything is working fine and maintenance is up to date. We dont feel safe driving the car

- Miami, FL, USA

While on the highway the vehicle began decelerating and increasing in rpms to maintain speed.transmission began slipping in and out of gear. From a stop it would take a few seconds before the vehicle engaged gear forward.smell of burning fluid came from the Sonata.this was a third and final incident with the power train. Previous incidents involved hard shifts that threw passengers back into their seats and sluggish response merging on freeway.

- Apo, AE, USA

Was driving to work and the car cut off in the middle of the road allowed me enough movement to turn in parking lot and get halfway in to a parking space

- Leland, NC, USA

On Saturday, October 13, 2018, I was in a parking structure looking for a place to park. I was on the ramp to the 2nd floor when for no apparent reason, my car accelerated and hit the vehicle in front of me and my vehicle immediately quickly reversed backwards and hit the vehicle behind me. The vehicle continued to move back and forth like a bumper car. I was trying to press the break but nothing happened. I started screaming for someone to help that the vehicle was out of control. After going back and forth about 5 times before being stopped by the vehicle behind me. The vehicle was stationary when this all happened.

- Hayward, CA, USA

Noticed clicking noise whem turning. Took the car to the in at dealership and they say axles are bad.

- Pittsburg, CA, USA

While driving in motion or after driving briefly after a complete stop. The emergency brake light may come on, or the actual brake lights would start to flicker for no reason. The rpms on the car would drop very low and then rise over 3000. The vehicle would then decelerate and not allow to go higher than 25 mph. The engine also makes a knocking noise. This has caused two near accidents, one being T-boned by another vehicle and another almost being hit in the rear of the vehicle by another vehicle. This has been stated to the local dealership at least twice and they state they cannot find anything wrong that would cause these issues. The vehicle has been taken to taylor Hyundai of augusta each time to be inspected.

- Aiken, SC, USA

While driving down the road my car is knocking out of gear, not getting acceleration. Pretty certain its the gear shifter. Also a burning smell comes from my motor.

- North Charleston, SC, USA

Press the start button and the car doesn't crank to turn on. Power to all other systems appears fine. I put the car in N then back to P and was able to turn the car on. Change battery and the battery on the key. Still having issues. No-start, no-crank due to gear selector range switch I was informed by Hyundai that my 2012 Sonata was not included in there campaign

- San Jose, CA, USA