The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power and the low battery warning light illuminated. In addition, the contact heard a rattling sound coming from the engine before the engine seized. The vehicle was towed to the dealer where it was diagnosed with a failed hybrid system and that the hybrid system needed to be replaced. The contact was also informed that the transmission was not the original transmission, and the cooler was damaged. The manufacturer was not made aware of the failure. The failure mileage was approximately 145,000.

- Anthony, NM, USA

The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated while driving at various speeds, the message "Pull Over. Stop the Vehicle" was displayed, and the vehicle failed to respond upon depressing the accelerator pedal. The contact veered to the side of the road and turned off the vehicle. The contact stated that the vehicle became drivable after waiting 30 minutes to an hour. The contact stated that the failure had been recurring while driving. Additionally, the contact stated that while reversing and depressing the accelerator pedal, the vehicle jerked, made an abnormally loud sound, and failed to respond. The contact shifted into park(P) and shifted back into reverse(R), and the vehicle jerked and responded. The contact stated that while driving at various speeds and depressing the accelerator pedal, the vehicle jerked and hesitated to respond. There was no warning light illuminated. The contact stated that she had taken the vehicle to an independent mechanic, where a diagnostic test was performed. The contact was referred to the dealer for assistance. The dealer and the manufacturer were not notified of the failure. The vehicle was not repaired. The failure mileage was unknown.

- Birmingham, AL, USA

The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated that while driving at an undisclosed speed and attempting to accelerate up a hill, the vehicle inadvertently lost motive power. Several attempts to restart and jumpstart the vehicle failed. The hybrid system warning light was illuminated on the instrument panel. The vehicle was towed to the residence and later towed to an independent mechanic, who determined that the engine had failed due to metal shavings in the engine oil. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 20V746000 (Engine) however, the VIN was not included. The manufacturer was not notified of the failure. The failure mileage was 55,000.

- San Jose, CA, USA

The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated while driving at various speeds, the vehicle hesitated and stalled while depressing the accelerator pedal. There was no warning light illuminated. The contact had taken the vehicle to multiple independent mechanics who were all unable to diagnose the failure due to no warning lights illuminating on the instrument panel. The contact then had the vehicle towed to the dealer where the mechanic was also unable to diagnose the failure. The mechanic informed her that the transmission needed to be replaced. The vehicle was not repaired. The failure mileage was approximately 130,000.

- Port Richey, FL, USA

The contact owns a 2012 Hyundai Sonata hybrid. The contact stated that while driving, an unknown warning light illuminated indicating to stop the vehicle do not drive. The vehicle was taken to clay cooley Hyundai of mesquite (16230 lyndon B johnson fwy, mesquite, tx 75150) and was diagnosed that the fuel pump that go to the transmission failed and was replaced. The contact stated that the vehicle was picked up at the dealer and while leaving the dealer, the vehicle stalled. No warning light was illuminated. Additionally, while depressing the accelerator pedal, the vehicle hesitated and stalled. The vehicle was taken back to the same dealer and the contact was informed that the transmission needed to be replaced. The vehicle was not yet repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 117,000.

- Dallas, TX, USA

The contact owns a 2012 Hyundai Sonata hybrid. While driving, the transmission failed and the vehicle stalled without warning. The vehicle was towed to bob brady Hyundai (4025 E boy rd, Decatur, il 62526, (217) 876-3800) where it was diagnosed that the transmission needed to be replaced. The vehicle was not repaired. The contact stated that the vehicle was taken approximately seven times to the same dealer, but the cause of the failure could not be determined. The contact stated that the dealer previously replaced the electrical component and the engine. The manufacturer was not made aware of the failure. The failure mileage was approximately 150,000.

- Decatur, IL, USA

The contact owns a 2012 Hyundai Sonata hybrid. While the gear was in park with the brake pedal depressed, the vehicle cautioned to move. Once the contact turned the vehicle off and on, the park warning indicator illuminated. Riverside Hyundai (8001 auto dr, riverside, ca 92504, (951) 643-5065) was contacted and informed the contact to call the manufacturer since the VIN was not included in a recall. The vehicle was not diagnosed or repaired and the failure recurred. The manufacturer was made aware of the failure and informed the contact to call NHTSA to file a complaint. The failure mileage was approximately 150,225.

- Riverside, CA, USA

Suddenly gave warning while driving not drive hybrid system failure. Please call me at [xxx] information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Modesto, CA, USA

2 major problems with this car. One is a brake issue and one is transmission issue I do have approximately 160K on the car now. The transmission issue goes back to when the car had approximately 40 to 50 K on it and was taken to dealer because of severe banging from one gear to another.. periodically it has done this since then..dealer could not get it to do it.. and said it could be normal.. car is well taken care of and now needs transmission..brakes have done wierd things. Once needed towing because of zero brakes, full hard pedal, no brake light on or any kind of warning..luckily I was in a slow drive thru.. towed and parked car..2 days later..everything is good..bizarr at the least if not absolutely dangerous.

- Cleveland, NY, USA

Yesterday the car drove fine untill about an hour before I went home. Then it started with the bumping/jerking when switching from electric to gas. Worse than it has ever been. Then the revving started, more than usual, and wouldn't accelerate. Then it was like the throttle stuck. Got the revving noice, but the eco wasn't burried at red, for about 1/4 mile before I was able to pull over into a parking lot. Shut off the car. Restarted and drove 1 mile to home. Revved a few times in that period.

- Goose Creek, SC, USA

The car began lurching forward intermittently at highway speeds (65+ mph) when travelling in a straight line on a flat highway on day 1, after 30 minutes of driving. On day 2, the car failed to shift gears at low speeds (<40 mph) while decelerating downhill on a city street, after running normally for 30 minutes at highway speeds. It coasted slightly uphill in first gear to the destination on a city street, unable to accelerate from 5mph. It was towed ($88) to a mechanic where it failed a road test, and the transmission and clutch assembly were pronounced dead. A new transmission and clutch assembly were installed and the engine (odo 131,000+) failed to turn over. $650 in labor to diagnose and attempt repair/replacement. Repairs were estimated at $8,100 and the kbb value was less than $3,200. The car is otherwise in excellent condition and is being sold to a junk yard with new tires under it.

- San Diego, CA, USA

While trying to accelerate at freeway speeds (50-60mph), the "eco guage" revs up but the car will not accelerate - slows down in the middle of traffic. The oil pressure warning lamp flickers on and off as well. After the car is stopped and turned off, the car functions normally. Mechanics are unable to retrieve any codes from the system. The car has intermittantly dropped into this mode at least 10 times since we first experienced the problem in July 2018. The problem occurs at freeway speeds causing the car to rapidly decelerate in fast moving traffic with no advance warnings. This situation requires immediate evasive action to remove the car from high speed traffic lanes so it can be shut down and towed to the Hyundai dealer. My wife and I consider this a life-threatening situation as it has occurred in places such as the bay bridge (with no shoulder) and a lengthy underwater tunnel (again with no shoulder). We have taken it to the Hyundai dealer service shop four times. They have replicated the problem and have tried various repairs - replace transmission oil pump, replace inhibitor switch, install new auxilliary battery, and - finally - replacing the transmission. Even after the transmission replacement, the car shut down while the mechanic was test driving it and provided a code to replace the crankshaft position sensor. The mechanics still are not certain they have fixed the problem. It appears as if Hyundai is aware of the problem as their technical support staff have a protocol for repairing the car. Given the intermittant nature of the problem, the fact that it occurs at high speeds, and the potential danger of having your car rapidly decelerate on busy freeways, I think this is a safety issue that needs to be addressed by Hyundai. Attached is the original service record that describes the problem (date 8/6/18). The most recent occurrence was 11/27/18.

- Incline Village, NV, USA

This has been happening on a daily basis for at least the last 4 months, some days are worse than others. Seems like the trans computer cannot make up its mind to engage or disengage and create a 'power loss' or acceleration loss. The car then bucks and clunks for a few seconds until it figures out what its going to do. Happens in low engine temps, car has not reached 1/2 way temp for several months, always runs 1, 2, or 3 bars from cold, replaced thermostat, radiator fan stopped working and replaced that. Sometimes the car will over rev and then catch making the car lurch forward or backward. This happens usually at stop signs or stop lights, but the RPM have been buried at high while driving then drops rapidly.

- Goose Creek, SC, USA

First incident, Sunday, September 9, 2018. While driving, car suddenly flashed warning lights, with message pertaining to the battery. Car decelerated extremely rapidly and became harder to steer. Pulled car over out of street as it lost power. It stopped. Lights remained on. Turned car off and then turned it back on. It cranked up and could be driven as if the incident never happened. There were no warning lights or warning message when the car was restarted. Second incident, Monday, September 10, 2018. While driving the car to the dealership for diagnosis of the problem, the car suddenly lost power again, the warning lights flashed again, and again it became hard to steer. This time driver was not able to pull the car over; it stopped in the street. Driver turned the car off, then turned it back on and drove to the nearest service station. A tow truck was called and the vehicle was towed to the dealership. The dealership stated the vehicle did not register any code that they could detect. They had a technician drive it from work to home each day and the vehicle never gave any problem. They could not find any problem at all with the vehicle that required service or repair. Vehicle was picked up on Saturday, September 16, 2018. The dealership waived the diagnostic fee since they were not able to diagnosis a problem. The vehicle has been traded-in. The issue was reported to Hyundai motor corporation.

- Birmingham, AL, USA

Upon obtaining my state inspection a couple weeks ago around 60K miles, my mechanic pointed out a slight "thunk" when turning the steering wheel and said to check for recalls. Since then it has become increasingly more noticeable. It "thunks" or clicks just to the right or left of center. First I only noticed it when parked, now I notice it when driving and the steering column rattles very loud when I go over even a small bump in the road. I am concerned that it is getting worse and trying to get an appointment to have it looked at. I see where this was a big problem with the 2011 model and now is starting with the 2012 around similar mileage. Clicking and rattling noise in steering column, not only while turning, but small bumps will make it rattle. Hope Hyundai issues a recall soon!!!

- Philadelphia, PA, USA

Engine started making a very loud knocking sound while driving 70-75 mph. Shortly there after the engine stopped and smoke came out of the hood. Towed the vehicle to a local Hyundai dealership that said the piston broke and went through the firewall.

- Port Orange, FL, USA

Vehicle transmission went up with no prior issues. Regular sonata 2012 engines have had recall on transmission - why not hybrids as they are having the same issue. Vehicle was in motion on highway and once in traffic had issues like going between 2nd and 3rd gear.

- Sharpsburg, MD, USA

I was driving southbound I-405 near renton, Washington around 7:30 a.M. morning rush hour traffic. Message flashed on "check charging system hybrid system warning safely stop and do not drive" at 80,725 miles. Drove to Hyundai dealer 4 minutes away who read check engine light error code diagnosing problem as hpcu reservoir module failure. Hyundai dealer replaced part under powertrain warranty at no cost to me. Cost of module was $3,527.45 plus $135 for 1 hr labor.

- Snohomish, WA, USA

The contact owns a 2012 Hyundai Sonata hybrid. The contact stated that the vehicle did not register the correct gear after it was shifted into reverse. The vehicle also jerked in the opposite direction it was shifted. The failure occurred without warning. Norm reeves Hyundai superstore (18900 studebaker road cerritos, ca) was contacted and the vehicle was not diagnosed. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was approximately 107,000.

- Lakewood, CA, USA

Drove vehicle on interstate 405 southbound at 60 mph and error message appeared that there was a hybrid system failure. Safely stop and do not drive. Towed to Hyundai dealership who determined from error codes that the power train failed at 63K miles. Hyundai had to replace the transmission.

- Snohomish, WA, USA