2015 Hyundai Sonata problems

“I am writing to formally report a serious and potentially dangerous safety issue involving my 2015 Hyundai Sonata. At approximately 93,000 miles, my vehicle experienced a complete engine failure, which resulted in Hyundai replacing the engine. Unfortunately, I am now experiencing another serious mechanical or electrical malfunction. While I am driving, my vehicle unexpectedly shuts off completely. When this happens, I cannot restart it immediately. I must wait approximately two to five minutes before the vehicle will restart. This situation is extremely concerning because it exposes me, my passengers, and other motorists to a significant safety risk. An unexpected shutdown while traveling on a public roadway could result in a serious accident. Given the vehicle's previous engine failure and Hyundai's subsequent engine replacement, I am requesting a thorough investigation into whether the current malfunction is connected to the replacement engine, its associated components, or another underlying defect. Specifically, I am requesting: A comprehensive diagnostic inspection to identify the cause of the unexpected shutdowns and delayed restarts. A review of the…”

“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…”

“I am filing this complaint regarding transmission and drivability problems with my 2015 Hyundai Sonata 2.4L following Hyundai Campaign 9C-2. My vehicle was running and driving perfectly before this update. I have always maintained it on time, followed proper maintenance schedules, and have records documenting its maintenance history. I never experienced these transmission issues before the update. The problems began immediately after the campaign was performed. In fact, I noticed the abnormal shifting before I even left the dealership after picking up my vehicle. Since the update, the vehicle has experienced poor and abnormal shifting behavior. I contacted the dealership to report the problem and also filed a complaint directly with Hyundai Corporate. I was told that Hyundai is aware of the issue, yet my complaint remains unresolved. I also located a document online indicating that Hyundai is aware of this problem. Additionally, I have seen numerous reports from other Hyundai owners describing similar transmission problems after receiving this same update. My vehicle has approximately 82,000 miles. The engine was replaced approximately one year before this…”

“The vehicle is currently at Greenway Orlando Hyundai for a fuel-system-related repair. During the dealership’s inspection, the dealership identified a crack in the fuel pump housing and a fuel leak. The dealership also provided photographs documenting the crack and the leak, and the vehicle has a very strong fuel odor. My primary concern is safety. A cracked fuel pump housing with a fuel leak presents a potential fire hazard. I do not believe it is safe to drive or operate the vehicle in this condition. The vehicle is being serviced in connection with Hyundai TSB 23-FL-004H, “Fuel Pump Filter Warranty Extension (TXXS), Inspection and Replacement.” The Prior Approval/goodwill issue is particularly important in this case. Note 2 on page 2 of TSB 23-FL-004H states that when a part not covered by the TSB is found to require replacement while performing the TXXS procedure, and that part is out of warranty, the dealership should submit a Prior Approval request for goodwill consideration before performing the work. When Greenway Orlando Hyundai identified the cracked fuel pump housing and the fuel leak, I asked the dealership to pursue this solution with Hyundai.…”

“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,…”

“The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at lower speeds, the steering wheel became difficult to steer in either the left or right direction. The Traction Control, Power Steering, and the high-beam warning lights were illuminated. The vehicle was taken to a local independent service center, where it was diagnosed with error codes: C167286, C126008, C136008, C126002, and C168808. The vehicle was not repaired. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 195,000.”