2012 Hyundai Sonata Hybrid: complete transmission failure

Filed Jun 16, 2026 · Brakes, Electrical · AZ

2012 Hyundai Sonata Hybrid well maintained by original owner, under 130,000 miles. May of 2025 AC stopped working intermittently (Hyundai dealer replaced AC hose). Aug 2025 AC stopped working AGAIN (same dealer could NOT identify problem). Car has consistent Hybrid System Warning! Safely Stop and Do not Drive messages lights and sirens when braking. Code PA186 comes up (low state of charge code for hybrid battery). December 2025 brought car back to SAME Hyundai dealer who NOW says car suddenly needs a 10k transmission (BUT still no idea what PA186 code is related to). Got transmission drained at different shop and NO NEW TRANSMISSION NEEDED! Every repair shop OUTSIDE OF HYUNDAI who has scanned for codes gets the PA186 error and say it is related to HYBRID BATTERY LOW STATE OF CHARGE (I am the original owner THUS lifetime hybrid battery warranty). June 2026 different Hyundai dealer for repair of AC and PA186 code. NEW Hyundai dealer says AC issue is NOT related to the PA186 code. They still dont know what PA186 code is but want to charge me $5100 for engine wiring harness electrical short. SIDE NOTE!! Engine wiring harness electrical short is known issue for ABS module recall 251 for this car. Hyundai has denied the engine wiring harness electrical short repair as part of ABS recall 251 warranty and STILL cant tell me why Hybrid System Warning Lights and PA186 code is come on. Is electrical issue really harness or HYBRID battery?? Car is currently at Hyundai dealer.

Filed Apr 29, 2024 · Transmission · 76,000 miles · TX

The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated that while driving at an undisclosed speed and depressing the brake pedal, the vehicle lunged forward. The vehicle was taken to an independent mechanic and diagnosed with automatic transmission failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 76,000.

Filed Oct 13, 2020 · Engine, Transmission · 117,000 miles · TX

Tl* 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.

Filed Oct 16, 2019 · Engine, Transmission · 150,000 miles · IL

Tl* 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. *dt

Filed Jan 5, 2019 · Engine, Transmission · 131,000 miles · CA

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.

Filed Dec 16, 2018 · Acceleration, Engine · 80,000 miles · NV

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.

Filed Jun 23, 2017 · Engine · 59,000 miles · CA

Vehicle has already had the transmission changed out under 30k miles and hybrid battery changed under 60k miles. I keep getting a hybrid system failure notice on the dashboard. One time it happened when the transmission failed on the 5fwy in burbank while driving to san francisco. Another time it happened on a toll road in irvine, ca where I had to get towed to the dealership. The warning is alarming and tells you not to drive. After the recent hybrid battery replacement I'm getting the hybrid system failure warning again after I drive it for a little bit and put it in park. I've been going to the tustin hyundai dealership in tustin, ca and the issue seems different everytime, but I'll never recommend a hyundai to anyone else given the number of forums and posts regarding the 2012-2016 hybrid sonatas engine issues.

Filed Dec 20, 2016 · Transmission · 63,000 miles · WA

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.

Filed Oct 22, 2014 · Transmission · CA

Recently my hybrid sonata car would not pickup speed especially between 10 and 40 miles per hour. It would also badly jerk while trying to accelerate or make high pitch sound without picking up speed. I had to pull to the side of the road couple of times and bit scared in driving it. Had the car towed to the dealer. The dealer after looking at the issue agreed to completely replace the transmission with the refurbished (from hyundai) transmission :(.

Filed Jul 21, 2014 · Transmission · 23,200 miles · TX

I had been experiencing a hesitation when accelerating, a lurch when hitting the brake as well as sometimes when accelerating as though the gears could not shift properly. This did not occur as often if the car was out of blue drive. This had been going on for about 4 months. I had taken it to a dealer and called a service department but none of them could explain why it might be happening and I could not make the issue repeat once I got it to the dealer. On saturday I went to drive my car, pulled out and was going about 40 MPH about 2 min after I had started the car and all of a sudden my foot was to the floor, the RPM was all the way up to red and my car was slowing down! I pulled over turned the car off and started it again, I pulled out again and it began to do the same thing but when I hit the brakes the car lurched forward worse than ever before. I pulled into a gas station cut the car off and got out to let my boyfriend try it (he had been following me in his car and did not know what was wrong). When he got in to try it he tried to put it in reverse and it would not shift at all. It was like it was still in park, but when he tried to put it back in park the car responded as though he had shifted it. Obviously something was very wrong with the transmission. We called the 24 hour roadside assistance and got towed to the nearest dealership. They mechanics spent all day taking it a[art and could not find the source of the problem. The senior mechanics came in on monday and said I would need a new transmission, that the existing transmission was "all burned up" they claim this is a rare internal problem and that a new transmission will fix the issue. All of this was covered under my warranty but it could have caused major problems had I been on the highway when this happened!