general problems of the 2015 Hyundai Sonata Hybrid

Component involved: hybrid propulsion system high voltage battery / ev battery electrical system power train incident summary: I am reporting a serious and repeated safety defect involving my 2015 Hyundai Sonata Hybrid. This vehicle has experienced three separate incidents where warning messages related to the ev/hybrid battery system appeared, followed by a sudden loss of forward propulsion. During these events, the vehicle would not move properly or lost the ability to accelerate safely. This defect creates a major safety hazard because it can occur while driving, increasing the risk of being rear-ended, stranded in traffic, collision, injury, or property damage. I transport my small children in this vehicle and no longer feel it is safe. Detailed timeline: initial incident: vehicle displayed warning messages involving the ev/hybrid battery system and lost the ability to move forward properly. Vehicle had to be shut off and restarted. Independent mechanic inspection: vehicle was inspected by an independent mechanic who advised the hybrid battery system likely needed repair or replacement and recommended service through Hyundai dealership. Dealer visit #1 – stew hansen Hyundai (3/18/2026): vehicle was taken to authorized Hyundai dealer for diagnosis. Dealer stated they could not duplicate the issue and no repair was made. Second failure: after release from dealer, same dangerous loss-of-power condition occurred again, resulting in towing and additional inconvenience. Dealer visit #2 – stew hansen Hyundai (4/8/2026): vehicle returned to dealer for same issue. Dealer performed software update and stated this should correct problem. Dealer advised vehicle had been driven approximately 40 miles and was safe to release. Third failure (4/12/2026 approx. ): only two days after picking vehicle up on 4/10/2026, same warning messages and propulsion failure occurred again. Safety concern: this repeated loss of propulsion without warning is extremely dangerous.

Idle and warning to not drive, 2025 very subtle cut off now full warning.

The contact owns a 2015 Hyundai Sonata Hybrid. The contact took the vehicle to the dealer to be repaired under NHTSA campaign number: 23v651000 (service brakes, hydraulic) and manufacturer recalls: 964 (auxiliary canister installation), 966 (engine monitoring module, ecu software update), and 994 (hybrid safety fuse). The contact stated that after the repairs were completed, while attempting to start the vehicle at the dealer, the vehicle failed to start. The vehicle remained at the dealer who was unable to determine the cause of the failure. The vehicle had not been repaired. The manufacturer was made aware of the failure and confirmed that the vehicle was not covered under warranty for any further repairs. The failure mileage was 170,000.

The contact owns a 2015 Hyundai Sonata Hybrid. The contact stated while driving at various speeds, a message advising to pull over and to park the vehicle was displayed. The vehicle was taken to the dealer for diagnostic testing several times. The dealer replaced the hecu and the battery inverter assembly; however, the failure persisted. Additionally, the contact stated that while his son was driving at an undisclosed speed, the contact's son noticed that there was white smoke coming from the rear middle seat of the vehicle. An unknown warning light was illuminated. The contact's son pulled to the side of the road and turned off the vehicle. The vehicle failed to restart and was towed to the dealer, where it was diagnosed that the hybrid battery pack had failed, causing the hybrid battery to melt. The dealer determined that the hybrid battery pack needed to be replaced. The vehicle was not repaired. The contact related the failure to Hyundai campaign number: 994. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 37,000.

Was driving about 25 mph and it sent warning lights and stuttered and died in front of railroad tracks. Very lucky it didn't die on the tracks.

Driving in rush hour traffic about 25 mph and car stuttered warning light came on and said to pull over, but everything shut down before I could. I blocked traffic for 6 hours. Did not get into an accident, but was very close to one. Everything shut down including hazard lights. I was unable to exit vehicle due to heavy traffic.

Tl- the contact owns a 2015 Hyundai Sonata Hybrid. The contact stated that while driving at 65 mph, the sound of a loud pop was coming from underneath the vehicle front passenger side. The contact noticed smoke start emitted from the front passenger side floor panel. There was no warning light illuminated. The contact coasted to the side of the road and was able to exit the vehicle where he noticed flame was coming from underneath the center of the vehicle and then it burst into flame. The fire department extinguish the fire. The fire department filed a report. The vehicle was towed to a tow lot. The vehicle was not taken to a dealer or an independent mechanic for a diagnostic testing of the failure. The vehicle was not repaired. The manufacturer was notified of the failure but did not offer further assistance. The approximate failure mileage was 35,000. The VIN was not available. Aw.

Tl the contact owns a 2015 Hyundai Sonata Hybrid. The contact stated that the vehicle shut down several times without warning while driving various speeds. The contact was uncertain as to what caused the failure, but felt it may be related to TSB number: 06-01-004-1. Keffer Hyundai (9010 e independence blvd, matthews, nc 28105, (704) 247-5645) was made aware of the failure and planned to schedule a diagnostic appointment. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was not available.

Hybrid system warning lights turned on while driving on the highway, illuminated "do not drive, pull over safely". Tried to pull over safely and the car stalled and wheels locked. Could not pull over to get out of traffic.

It has overheat problem that Hyundai service couldn't fix. It broke down 6 times and was 3 times in the shop. 4/2/17, I was on fastest lane on 101 freeway in downtown la. Suddenly the car alarm beeps. Dash board displayed "hybrid system warning, safely stop and do not drive". The gas pedal was hard to press, (guess it goes into protection mode. ) fortunately it was in rush hour traffic that no car ram into me from behind. I forced the car switched lanes and exit freeway. After I parked, the car frozed. I can't turn on the emergency signal. Can't switch the gear to park, can't turn off the engine. . . I exit the car and wave cars behind me move ahead, then I got back the car and was able to turn off the engine. After it was off for 30 seconds, I can turn the engine back on and the car functions like normal. It was under 18000 miles. The service department says the coolant leak and replaced it. 5/15/17, while driving on freeway, I felt the car was into protection mode, hard to press the accelerator. But the alarm didn't sound off. I sent it in and the service couldn't duplicate the problem so they reset the computer of the car. 6/5/17 the car was parked in hot sun in ps for 30 minutes while me and my realtor go to check a house. I started the car following my realtor. I turned on the ac and the alarm goes off, same warning sign displayed and the car just froze. Hyundai sent a tow truck an hour later. After in the shop overnight, the service dept says they fixed it. 6/14. In ps again. The car was parked in hot sun. I got in and turn on the engine. Alarms goes off same warning sign. 6/26, with a friend on way to julian, the car engine thrust the car forward, a small icon lit up. I slowed down and parked , the alarm goes off, same warning words on dashboard. After let the car cool off, I was able to drive but 20 minutes later it happened again.

I was driving on the highway when suddenly the check charging light system warning came on, all 3 lights for oil, battery, and engine came on at the same time! the car stalled was not possible to stear and brakes didn't work. . . I had to coast luckily I was only in second to right line and easily got to emergency lane!! this happened on 101 in California during a busy time!!!.

While driving my car started alarming saying check charging system. . . It immediately went to 15 miles and hour while I was on i95 where speed limit is 65 mph. By the time I got home and turned the car off it would not turn back on. Ive had this car for a year and a half. I bought it new.

About an hour into driving home on the freeway, my car alert system went off and the car automatically began to decelerate and the dashboard display showed instructions to check hybrid charging system and to check surroundings and to pull over when safe and to not drive vehicle. The check engine light, the needs maintenance light and the check oil light all came on. After about 15 secs my vehicle lost all power but did not turn off; the steering wheel became locked. I placed the car into park and restarted it and the warning alert alarm ceased, but now the check engine light stayed on. The steering wheel was movable again and I was able to pull to the shoulder where a California highway patrol officer pulled up and asked me if I was having trouble. After our conversation, I was able to continue the additional 40 mile drive home as the local Hyundai dealerships were closed until the next day, Saturday March 18. I was able to drop my car off in the afternoon but due to their booked schedule, it could not be looked at until Monday March 20th and stayed over night. The technician called me that day and stated that the car test ran on it came back passing and no issues found and that they drove it about 20 miles and no issues and I was able to pick up my car on Tuesday. However, the same system issue happened 3 more times before I was able to take it back into the dealerahip later that week and it has been there as of 4/21/2017. I received a call today that a replacement hybrid battery was installed and after more tests I may get my car back.

As I was driving down the road, a warning sign appears in my dash that says do not drive. . . . Mean while im already driving. . . . Cars starts to stall and wheel locks. I get the car towed to the dealership that night and the next day. . . Which is today I am waiting for someone to call and ask me what happens and nothing. . . So I decided to drive there and what do I see. . . . . My car sitting on the side like no one cars that is there. . . When I go in I find out that there is only 1 person that works on hybrids and they don't know when they will be able to take a look at it. . . Oh and lets not forget they don't do loaner cars. . I just bought this car 1 year ago from this same dealership. . . They cant give me any type of estimate of when the tech will be able to look at my car. . . This is very bad service!!! why would my car stop driving after having it only a year?????.

The contact owns a 2015 Hyundai Sonata Hybrid. While driving approximately 35 mph, the vehicle stalled and lost power without warning. The vehicle was coasted to the side of the road and was restarted. The vehicle was taken to a dealer who was unable to duplicate the failure. The manufacturer was made aware of the failure and stated that nothing could be done. The failure recurred and was not remedied. The failure mileage was approximately 24,000.

Transmission acts like it is slipping and shifts abnormally in forward and reverse, driver window up/down button doesn't work correctly it only makes the window go up 1/4 of the way so you have to let go and press it again. The radio keeps showing and error message waiting to get into the dealer.

When pressing the accelerate pedal there seems to be a delay in response. The delay can be as short as a few milliseconds to almost 3 entire seconds. This problem happens randomly, and makes my wife and I very nervous when trying to maneuver or proceed into traffic after being stopped.