2015 Hyundai Sonata brakes problems

Filed Oct 28, 2026 · Brakes, Electrical · CO

On Wednesday, October 21, 2026, our 2015 Hyundai Sonata with the 2.4L Theta II GDI engine suffered a sudden, complete engine seizure while traveling about 75 mph on I-25 Southbound near Castle Rock, CO. A family member was driving. Warning lights across the car began flashing, the engine made a loud grinding noise, and the brakes stopped working. Over a long distance, the driver was able to get the car onto the shoulder and bring it to a stop, then engage the parking brake. There was no collision and no injuries, only because traffic was light. The car was towed to a repair shop, then transferred to a second shop, which determined the engine had seized and requires full replacement. This vehicle is covered by Hyundai's Theta II GDI engine campaigns for connecting rod bearing failure. On October 26, 2026, Hyundai told us the Knock Sensor Detection System software update (Campaign 953) was never completed on this vehicle and declined coverage. Neither we nor the prior owners, who are family members, recall receiving any notice of this campaign. All previous check engine lights were diagnosed and repaired at independent shops, including an intake manifold replacement in April 2024, and no shop ever identified an open engine campaign. A full engine seizure at highway speed, combined with the loss of braking, creates a serious crash risk for the driver and surrounding traffic.

Filed Aug 16, 2026 · Brakes · TX

Brake lights not working properly.

Filed May 1, 2026 · Brakes, Engine · WI

I have the 2015 Hyundai sonata with the 2.5 GDI engine that eventually will seize due to internal damaged caused by manufacture design flaws. My Hyundai threw a P0010 code which causes my car to idle high and causing low vacuum affecting my brakes. I had a diagnostic test done at a Hyundai dealership that told me it was a cvvt cam sprocket issue and that it was the beginning of the end of the engine, They quoted me 3700.00 but the engine was to far gone and this repair would only accelerate the engine to seize. They said since the engine isn't seize Hyundai will not cover the cost to repair or exchange the engine, I contacted the Hyundai customer service who stated since the repair that is needed wasn't the root cause of the problems associated with the engine swap warranty they were not going to help me even though I explained to them that the cars high accelerating and the braking system been jeopardized and been told the engine is beyond repairs I feel Hyundai should reconsider their decision and help a loyal customer. I have purchased 12 Brand New Hyundaj since 2001. The customer Representative was Extremely un Professional even suggesting I scrap my car, Also I contacted My Hyundai service Technician who said Hyundai customer service never contacted them about my car, When they said they spoke with the technician. Also I received an Extended warranty on the 2.4 GDI engine from Hyundai who many Hyundai customers are or have dealt with.I also purchased an Extended warranty Which I believe should have been extended as well Thank You

Filed Feb 25, 2026 · Brakes · VA · crash

I was turning into a parking spot and the car accelerated unexpectedly. I slammed into a snow bank and my front bumper was damaged.

Filed Jan 19, 2026 · Brakes, Electrical · MS · 1 injury

My 2015 Sonata will stall out dropping speeds to 12-24 when i slightly merge, when I turn ect. Then it won’t accelerate for what seems like 10 minutes realistically 2 minutes maybe 3 Then will slowly regain speed. I’ve almost wrecked twice Share care with daughter and she’s been victim to it way way more. This is scary and Hyundai won’t stay behind their product Local dealership won’t fix recalls so we have to go over 120 miles for repairs. The recall isn’t even for transmission engine

Filed Sep 20, 2025 · Brakes, Electrical · FL

The rubber stopper for the brake light switch on the brake pedal deteriorated and fell apart. This resulted in the brake lights remaining on constantly, cruise control being disabled, and low battery voltage.

Filed Jul 11, 2025 · Brakes, Engine · KY

The turning signal gives the opposite signals sometimes.

Filed Jun 20, 2025 · Brakes, Electrical · CA

The car has had an electrical issue ever since taking to to get a recall around may of 2023. It will randomly brake and shift the transmission badly while downshifting. I feel as if my make and model falls under the theta II campaign they had to replace certain engines for having a knocking rod be fault and release shaving into the engine causing it to misfire. Not only that but the electrical issue is completely random it happens atleast once or twice a week. It had began ever since I took it for a recall, and when I took it back they found no issue and left food in the back of my car and the chairs leaned back. This was the Fontana Hyundai dealership

Filed May 12, 2025 · Acceleration, Brakes · IL · crash

My 2015 Hyundai Sonata has demonstrated multiple instances of unintended acceleration and braking failure: April 20, 2024 – While idling in a drive-thru line, the vehicle suddenly lurched forward without any attempt to accelerate and crashed into the vehicle in front of me. I was unable to stop it. This resulted in the other car being totaled. I took it to a Hyundai dealership afterward, but they found no definitive cause. April 4, 2025 – My daughter was driving and attempted to stop at a red light. Despite applying the brakes, the car did not stop and continued through the intersection, striking the door of another vehicle. May 12, 2025 – Today, while using cruise control set to 55 mph, the car began accelerating beyond the set speed without input. It appears the cruise control system is malfunctioning and not disengaging as expected. The vehicle currently shows no open recalls, but I found that similar issues were previously investigated under the federal safety agency action DP21003 for this model year. These incidents occurred months apart, but the behavior is consistent and extremely dangerous. I am requesting a formal investigation. The safety of my family and others on the road is at risk.

Filed Jan 15, 2025 · Brakes, Driver assistance · FL · 1 injury

Location: [XXX] Description of Incident: On a rainy morning, while driving to work, I encountered a sudden lane cut-off by a speeding truck as I exited a school zone. I applied the brakes to avoid a forward collision, but the brake system failed entirely. This resulted in the loss of vehicle traction, causing the car to spin out uncontrollably. The vehicle collided with an island, bounced into oncoming traffic, and sustained severe damage, including: •Tires ripped off the rims •Front axle damage Injuries: I sustained a lightly sprained neck as a result of the incident. Vehicle History: The vehicle had been in the custody of the Hyundai dealership just days prior to this incident for an engine/powertrain recall and replacement. The dealership held the car for over a week to address the issue. However, shortly after retrieving the vehicle, the brake failure occurred. Observations and Concerns: •The brake failure occurred after recent service by the manufacturer dealership. •Hyundai vehicles are known to have documented brake system issues, which may have contributed to this incident. •This failure nearly resulted in a life-threatening accident. Action Requested: I am requesting an investigation into the service performed during the recall and the brake system failure. It is imperative to determine accountability and address any potential defects to prevent future occurrences. [XXX] [XXX] - Victim and incident reporter. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)