Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2012 Hyundai Sonata Hybrid owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owned a 2012 Hyundai Sonata. The contact stated that while driving at 75 MPH on the highway, while depressing the accelerator pedal, the vehicle failed to accelerate. No warning lights illuminated. The contact veered over to the right side of the road, turned the vehicle off, and she noticed smoke coming from the engine. A bystander behind her noticed the flames coming up from the engine. The contact mentioned she exited the vehicle and called 911. No injuries were sustained. No medical attention was required. A police report was filed. The fire department extinguished the fire. The vehicle was destroyed. The vehicle was towed to Atow lot. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 160,000.
The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated while driving at various speeds, the vehicle slowly start to lose motive power. There was smoke coming from the engine compartment. The contact stated that the check engine warning light was illuminated. The contact then received notification of NHTSA campaign number: 20V746000 (Engine). The vehicle was then taken to the local dealer where it was diagnosed with the engine needing to be replaced. The dealer stated that they could not service the recall until the engine had failed. The vehicle was not repaired. The manufacturer had not been informed of the failure. The failure mileage was approximately 72,000.
The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated while driving at various speeds, there was an intermittent knocking sound coming from the engine. There was no warning light illuminated. A few months later, the engine began to overheat while driving at various speeds and a message stating "Do Not Drive, Please Pull Over" appeared on the instrument panel. The contact had the vehicle towed to a dealer where she was informed that she needed an engine replacement. The contact then had the vehicle towed an independent mechanic for a second opinion and he discovered that the engine was cracked, and that water had leaked into cylinder #2. The mechanic then informed her t that the vehicle had been placed under NHTSA Campaign Number: 20V746000 (Engine) and referred her to another dealer. …
The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated that while driving at approximately 50 MPH, the brake pedal was depressed and the vehicle began to stall. The contact stated that the accelerator pedal was then depressed but the vehicle would not accelerate as needed. The contact stated that the check engine warning light and the hybrid engine warning message was displayed and advised the driver to "Safely Stop and Do Not Drive" the vehicle. The contact pulled over and turned off the vehicle. The vehicle was restarted and the contact parked the vehicle in a parking lot and turned off the vehicle and waited for a while. The contact then restarted the vehicle and the check engine warning light remained illuminated. The vehicle was taken to the local dealer where it was diagnosed that the engine control module (ECM) needed to be replaced. …
The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated while driving 45-50 MPH, the vehicle started making an abnormal beeping sound. The contact stated that the check engine warning light and several other unknown warning lights illuminated, and the vehicle began to stall. The contact stated that she pulled into a parking lot, parked, and turned off the vehicle. The next day the vehicle was towed to the dealer who diagnosed that the system hybrid module needed to be updated. The contact stated that the system hybrid module was updated; however, the failure reoccurred while driving. The warning message "Hybrid system Warning; Safely Stop and Do Not Drive", and the brake warning light and an unknown warning light illuminated. The contact also stated that the vehicle made an abnormal grinding sound. The dealer was notified of the failure. …
The contact's wife owns a 2012 Hyundai Sonata Hybrid. The contact stated while driving approximately 65 MPH, there was an abnormal banging sound coming from the engine compartment. The contact stated no warning light was illuminated. The vehicle lost motive power and decelerated to 30 MPH. The contact pulled over and had the vehicle towed to his residence. The Customer Service Department was contacted and the representative suggested that the vehicle be taken to an authorized dealer to be diagnosed. The contact was informed that the connecting rods failed and punctured the engine block and the engine needed to be replaced. The vehicle was not repaired. The manufacturer had not been informed of the failure. The dealer had been informed of NHTSA Campaign Number: 20V746000 (Engine) however, the dealer stated that the vehicle was past warranty period. …
The contact owns a 2012 Hyundai Sonata. The contact stated while driving at 70 MPH, the oil pressure warning light illuminated and the vehicle started losing motive power. The accelerator pedal was depressed but the vehicle failed to respond and jolted. The contact veered to the side of the road. The contact turned off and restarted the vehicle. The contact continued to drive at a slower speed however, the failure reoccurred several times while driving to her residence. The vehicle was taken to the dealer who informed the contact that the failure was associated to Manufacturer Recall Number: 198. However, the dealer informed the contact that they could not repair the vehicle under the recall. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and a case was opened. The failure mileage was approximately 168,000.
The contact owns a 2012 Hyundai Sonata Hybrid. The contact received a recall notification for NHTSA Campaign Number: 20V746000 (Engine) however, the contact was unable to schedule a recall repair appointment with the dealer as the dealer would not return his phone calls. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that he had been hearing abnormal sounds coming from the engine while driving. There were no warning lights illuminated. The contact also stated the vehicle had been consuming a significant amount of gasoline. The vehicle was not diagnosed nor repaired by an independent mechanic or dealer. The dealer and manufacturer were not notified of the failure. The approximate failure mileage was 41,500. Parts distribution disconnect.
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.
The contact owns a 2012 Hyundai Sonata Hybrid. The contact stated that he had received notification of NHTSA Campaign Number: 15V568000 (Engine). The contact took the vehicle to a dealer where the recall was serviced. Soon after the recalled pair, the "Hybrid System Warning Light, Safely Stop and Do Not Drive," warning message appeared on the instrument panel. The contact had the vehicle towed to a dealer where it remained in their possession. The manufacturer was notified of the failure but offered no assistance. The contact was given an estimate for the repair but was declined. The vehicle had yet to be repaired. The failure mileage was 155,000.
Related recalls
Engine
Hyundai Motor America (Hyundai) is recalling certain 2015-2016 Veloster, 2012 Santa Fe, 2011-2013 Sonata Hybrid, and 2016 Sonata Hybrid vehicles. The connecting rod bearings inside the engine may wear prematurely, which over time can result in engine damage.
Remedy: Hyundai will notify owners, and dealers will inspect the engine. If bearing damage is found, the engine will be replaced. Dealers will also install a software update containing a new Knock Sensor Detection System…
NHTSA investigations
Engine Fires
On March 29, 2019, the Office of Defects Investigation (ODI) opened two Preliminary Evaluations (PE19-003 on Hyundai and PE19-004 on Kia) to broadly investigate incidents of non-crash fires (regardless of origin or operational status of the vehicle) on various model year Hyundai and Kia vehicles.
Loss of Motive Power
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021.
Engine complaints in other Sonata Hybrid years
Frequently asked questions
How common are engine problems on the 2012 Hyundai Sonata Hybrid?
NHTSA has 70 complaints about the engine & cooling of the 2012 Hyundai Sonata Hybrid, 45% of the model year's 154 complaints. The component named most often is exhaust system › emission control › catalytic convertor (1 mentions).
Is there a recall for 2012 Hyundai Sonata Hybrid engine problems?
Yes — NHTSA recall 20V-746 (engine, Dec 1, 2020). Recall repairs are free at authorized dealers.
At what mileage do 2012 Hyundai Sonata Hybrid engine problems start?
Half of the complaints with a recorded mileage happened before about 97,000 miles, and 8% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 5 fires and 2 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.