The contact owns a 2012 Hyundai Sonata. The contact stated that while driving at 30 MPH, the check engine warning light illuminated, the engine started knocking, and smoke emitted from under the hood. The contact decelerated to approximately 15 MPH and drove to her nearby residence. Upon inspection, the contact observed green fluid under the hood. The vehicle was towed to an independent mechanic, where it was diagnosed that the engine had failed and the head gasket was blown. The mechanic informed the contact that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 100,000.
2012 Hyundai Sonata: check engine light
133 of the 1,559 complaints about the 2012 Hyundai Sonata describe check engine light.
- owner complaints
- 133
- of this car's complaints
- 9%
- typical repair cost reported
- $1,400
- typical mileage
- 94,750
- recalls
- 2
Is there a fix? There are 2 recalls and 44 service bulletins for this area of the car. See below
Check engine light by model year
What owners say
Around the end of May 2026, my vehicle stalled without warning while traveling at highway speed. The engine light and EPS warning light illuminated simultaneously. The engine cranks but will not start. The vehicle was towed to a Hyundai dealership on June 15, 2026 where the engine failure was confirmed. My safety was directly at risk. The vehicle lost power on an active highway with no warning, creating a collision hazard for myself and other drivers. The failure has been confirmed by the dealership. Hyundai Motor America acknowledged the engine failure falls under the TXXI Settlement Agreement and offered a buyback or cash settlement. However, Hyundai has had physical possession of my vehicle since June 15, 2026 and has repeatedly failed to provide a written buyback offer despite multiple commitments to do so. Prior warning signs included the engine and EPS lights activating at the moment of failure. No prior warning lamps appeared before that day. The vehicle has 2 open safety recalls as of the date of purchase in November 2025.
Knock sensor needs to be replaced upon evaluation of an inspection on March 27, 2026. It failed a mission codes and upon my understanding the knock sensor one circuit range performance pink wonder single sensor is an engine failure as well as I did an ODB test myself on May 19 of 2026 for the Knox sensor as well and the check engine dominator reading at 2111 the the code indicated that bank one Knox and electrical circuit was out of it upper range or had it perform problem for a predetermined period of time and the code is P0326 and the secondary DTC is a combustion vibration sensor a circuit range performance which affects the powertrain. Also, I have switches with the electrical features in the vehicle as far as the ABS and the steering wheel controls and glitching for the cigarette adapter and plug-in area as well on top of the rear passenger side window, having issues with going up and down.
My 2012 Hyundai Sonata cut off and stopped working! The vehicle locked up in the middle of a main street and would not start back up causing a very unsafe situation. There were no check engine lights on or anything at the time of the incident I immediately had the vehicle towed and inspected it has been determined that the engine is failing! Upon research I found out that these engines have had recalls in the past. Carfax shows that the vehicle has been taken in for routine maintenance and oil changes when needed. I am looking to see if the engine replacement could be covered for this vehicle.
While driving on the highway with my two minor children, my vehicle suddenly shut off without warning. I lost power in the middle of traffic, which was extremely dangerous — we were nearly rear-ended and had to coast to the shoulder. The check engine light had been on for some time prior to the incident, but there were no other warning messages. After being towed, the car would not start again, even after attempting to jump-start it. A mechanic inspected it and believes the engine is seized. I later discovered that my 2012 Sonata is equipped with the Theta II engine, which is known for sudden failure due to oil starvation or bearing wear. Although there are no current recalls on my VIN, the symptoms are consistent with the known Theta II engine defect. This situation put me and my children at serious risk, and I believe this failure needs to be addressed as a safety issue.
The contact owns a 2012 Hyundai Sonata. The contact stated that while attempting to start the vehicle, the vehicle briefly hesitated before starting. After starting the vehicle, the vehicle returned to normal functionality, but the failure became a regular occurrence. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the engine. The contact was advised to take the vehicle to the dealer for assistance. The vehicle was not repaired. The manufacturer was notified of the failure but provided no assistance. The failure mileage was 137,000.
Car engine light is flashing
The contact owns a 2012 Hyundai Sonata. The contact stated that while driving 30 MPH, the vehicle shut off. The contact restarted the vehicle, and an abnormal knocking sound was coming from the engine compartment with the check engine warning light illuminated. Despite the vehicle repeated engine shut off failure, the contact was able to drive the vehicle to an independent mechanic for service. The vehicle was diagnosed with a rod bearing failure. Neither the dealer nor the manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 124,000.
On July 29, 2024, my 2012 Hyundai Sonata Hybrid was parked in our driveway. About 10 minutes later an engine fire started that consumed the car. The local Fire Departmemt put out the fire but the car was totaled. The fire also destroyed a storage shed and some windows were damaged. The car was taken to the Hyundai Dealer for servicing when the engine light came on on March of 2024. The car was left for a few days with the dealer. the federal safety agency Recall Number 23V651000 was not repaired during that service call.
The contact owns a 2012 Hyundai Sonata. The contact stated that while her daughter was driving at undisclosed speeds, the vehicle was jerking abnormally. The passenger's side front tire was extremely hot. The contact stated that the RPM increased to high, and the vehicle lost motive power while driving. The contact stated that while the accelerator pedal was depressed, the vehicle was slow to respond. There was an abnormal electrical burning odor detected. The vehicle was hard to start. The contact stated that the check engine and ABS warning lights were illuminated. On several occasions, the vehicle was taken to the local dealer, who was unable to retrieve any DTC trouble codes. The bearing was fine but was replaced at the owner's request. The mechanic test-drove the vehicle for five hundred miles but was unable to duplicate the failure. The mechanic informed the contact that the ECM was fried. The ECM was replaced, but no update was provided. Additionally, the mechanic informed the contact that the wiring harness had a short circuit and that the wiring harness needed to be replaced. The vehicle was repaired, but the failure persisted. The manufacturer was contacted, but no assistance was provided. The failure mileage was unknown.
Check engine light comes on, brake system malfunction warning message appears and says to pull over, vehicle goes into limp mode. Hyundai dealership says $150 to diagnose problem.
There is a widespread issue with the 2012 Hyundai Sonata hybrid transmissions failing as driver's are driving resulting in extremely dangerous and life threatening situations. It is hazardous for drivers, passengers, and other vehicles on the road. I was driving my 2012 Hyundai Sonata hybrid on an expressway when with zero warning the car stopped driving. I easily could have had a car slam into me from behind at a high rate of speed. This was when the car had 79,672 miles on it. The transmission was replaced by Hyundai under warranty. The second transmission on the vehicle has now failed with only 84,984 miles on that transmission. This time, once again, no warning. No engine lights came on or anything. My car began to stop driving on a main highway with a large line of cars behind me. Once again causing a hazardous dangerous condition for me and others. This time, I was able to get to the side of the road. So not only was I in danger while driving and the car failed with zero warning, I was stranded on the side of the road with my very young child in the car. A transmission failing with zero warning with a mother and young child stranded on the side of the road is a secondary hazard to the possibility of us having been hit by a driver behind us as the transmission failed. There are many forums and reports of people having transmission failures with this make and model. Others specifically shared how dangerous of a position it also put them in with no warning. One other gentleman in a forum detailed how he was on an expressway when it happened and how dangerous it was for him. The quantity of not just first transmissions, but second and third transmission replacements failing in the 2012 Hyundai Sonata hybrid and in some cases close model years is alarming. Hyundai needs to take accountability for their poor craftmanship and protect their consumers. This car is a death trap and will get people severely injured or killed.
Service bulletins that may apply
- Higher-than-expected engine oil consumption
- Higher-than-expected engine oil consumption
- This bulletin provides important checkpoint guidelines when performing engine oil and filter change services.
- Follow the guidelines outlined in
- Check Engine warning lamp illuminated with DTC P1326 and/or engine may exhibit abnormal noise or no...
- Applicable vehicles with 2.0L T-GDI and 2.4L GDI engines may experience the Check Engine warning lamp...
- The warranty coverage for engine long block repair or replacement regarding engine damage or malfunction...
- The warranty coverage for engine long block repair or replacement regarding engine damage or malfunction...
Related recalls
Engine
- What is wrong
- Hyundai Motor America (Hyundai) is recalling certain 2011-2014 Sonata and 2013-2014 Santa Fe Sport vehicles previously repaired under recall numbers 15V‑568 and 17V‑226. The high pressure fuel pipe that connects to the fuel pump outlet may have been damaged, misaligned, or improperly torqued during the engine replacement procedure, allowing fuel to leak from the pipe.
- Risk
- A fuel leak in the presence of an ignition source can increase the risk of a fire.
- Remedy
- Hyundai will notify owners, and dealers will inspect and replace the fuel pipe, as necessary, free of charge. The recall began March 1, 2019. Owners may contact Hyundai customer service at 1‑855‑371‑9460. Hyundai's recall number for this recall is 180.
Recall number 18V934000 · Recall details
Engine
- What is wrong
- Hyundai Motor America (Hyundai) is recalling certain model year 2011-2012 Sonata vehicles manufactured December 11, 2009, to April 12, 2012 at Hyundai Motor Manufacturing Alabama and equipped with either a 2.0 liter or 2.4 liter Gasoline Direct injection engine. In the affected vehicles, metallic debris may not have been fully removed during manufacturing of the engine crankshaft. If the debris was not completely removed, oil flow may be restricted through the connecting rod bearings, causing connecting rod damage. A worn connecting rod bearing will produce a metallic, cyclic knocking noise from the engine and possible engine failure.
- Risk
- Engine failure would result in a vehicle stall, increasing the risk of a crash.
- Remedy
- Hyundai will notify owners, and dealers will inspect the vehicles and replace the engine assembly, as necessary, free of charge. Additionally, Hyundai Motor America will increase the warranty for the engine sub-assembly (short block) to 10 years/120,000 miles for both original and subsequent owners of 2011 and 2012 Sonatas manufactured at Hyundai Motor Manufacturing Alabama equipped with 2.0 liter and 2.4 liter Gasoline Direct injection engines. Interim notifications were mailed to owners starting on October 8, 2015. A second notification will be mailed when parts are available. Owners may contact Hyundai customer service at 1‑855‑671‑3059 or by visiting www.HyundaiUSA.com/Campaign132. Hyundai's number for this recall is 132.
Recall number 15V568000 · Recall details
Questions about the 2012 Hyundai Sonata check engine light
Is check engine light a common problem on the 2012 Hyundai Sonata?
133 of 1,559 owner complaints about the 2012 Hyundai Sonata (9%) mention check engine light. The model year with the most reports is 2015.
How much does it cost to fix check engine light on the 2012 Hyundai Sonata?
Owners who mentioned a price put the repair at about $1,400 (median of 11 complaints that include a dollar amount). Costs vary with mileage, warranty and where the work is done.
Is there a recall or service bulletin for this on the 2012 Hyundai Sonata?
There are 2 recalls and 44 service bulletins for the same area of the car. Check them below with your VIN.
Other symptoms on the 2012 Hyundai Sonata
Engine failure 188Knocking 150Stalling 146Steering noise 94Fire or smoke 91Airbag light 84Loss of power 84Won't start 58Headlights 46Warning lights 38Harsh shifting 37Jerking 37Hesitation 33Pulling 33Adaptive cruise 26Power steering loss 26Grinding brakes 24Fuel pump 22Oil consumption 18ABS 17Fuel smell 17Brake failure 15Overheating 15No deployment 13Battery drain 13Sudden acceleration 13Sunroof shattered 12Fuel gauge 11Won't shift 11Steering lock-up 10Transmission failure 10Ball joint 9Key fob 9Door locks 8Seat belt 8Fuel leak 6Shudder 6Misfire 5Tire blowout 5
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