2025 Hyundai Santa Fe

While operating the vehicle, the vehicle suddenly began severely hesitating and stalling. During the incident, engine RPM surged to approximately 6,000 RPM and accelerator pedal response became abnormal. The vehicle was not responding normally to accelerator input, which significantly affected the ability to operate the vehicle safely. The vehicle subsequently recorded diagnostic trouble code P0304 – Cylinder 4 Misfire Detected. The abnormal operation of the vehicle during the incident was also captured on video. The vehicle was taken to an authorized Hyundai dealership for diagnosis. The dealership has advised that because the condition is not currently occurring and they have been unable to duplicate the problem, they may be unable to diagnose or repair the vehicle. The safety concern is not simply an illuminated check-engine light or a stored P0304 code. The concern is the combination of severe hesitation/stalling, abnormal accelerator response, and the engine surging to approximately 6,000 RPM while the vehicle was being driven. The cause of the condition has not been identified and, at the time of this complaint, the vehicle has not been repaired for the underlying problem. I am concerned that this condition could recur without warning while accelerating, entering or crossing traffic, or traveling at highway speeds. A recurrence could result in an inability to accelerate normally, unexpected vehicle behavior, loss of normal vehicle operation, or a collision. Hyundai has been notified of the issue and I have requested further technical investigation of the engine misfire as well as the transmission/TCU and electronic throttle/accelerator systems due to the high-RPM event and abnormal accelerator response. I am submitting this complaint because this appears to be a potentially serious safety-related defect and I want NHTSA to have a record of the incident and determine whether similar stalling, high-RPM, acceleration, transmission, or engine-misfire.

What component or system failed or malfunctioned, and is it available for inspection upon request? The vehicle suffers from an intermittent, total engine stalling and propulsion failure. Without warning, the engine completely shuts down while driving and automatically drops the vehicle into "Accessory (ACC) Mode". The vehicle is fully intact, operational when it restarts, and is available for immediate inspection upon request How was your safety or the safety of others put at risk? This issue has occurred five total times in live traffic, severely risking the safety of the vehicle's occupants and surrounding drivers. The most recent and dangerous incident occurred on the freeway in heavy, stop-and-go traffic. A sudden, complete loss of power on a high-speed freeway leaves the vehicle entirely vulnerable to rear-end collisions, as it leaves no room or momentum to safely coast to the shoulder. Has the problem been reproduced or confirmed by a dealer or independent service center? No. The vehicle has been brought to an authorized Hyundai dealership five separate times specifically to diagnose this exact stalling issue. Because the failure is intermittent, dealership service technicians have been unable to replicate the problem during their test drives or resolve the root cause. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle has been inspected five separate times by authorized Hyundai dealership technicians during the service appointments mentioned above. No police, insurance, or independent manufacturer representatives have inspected the vehicle yet, as the stalling has not yet resulted in a physical crash. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear?There are absolutely no dashboard warning lights, check engine indicators, error messages, or mechanical symptoms prior to the failures. The engine shuts down instant

While driving on the on ramp to [XXX] the car completely stopped and all systems shut off. There were two dash lights that flashed quickly with one being the check engine light but I did not see the other long enough to identify it. The dealership could not reproduce the issue but has the car now and is doing a more thorough evaluation. What component or system failed or malfunctioned, and is it available for inspection upon request? The engine stopped. Yes it is available How was your safety or the safety of others put at risk? Extremely dangerous as it came to a stop in the middle of the road. It was late at night so at that moment no one was behind me. Has the problem been reproduced or confirmed by a dealer or independent service center? no Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? no Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? no, the warning lights flashed on as the car died but disappeared once off. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Traveling in a 55 zone on Rt 27 and my vehicle lost power and said pull over and charge vehicle with engine on. I did this once and the battery went up to half way charge then I could start to drive again. Less than a half a mile up the road climbing a good size hill by the town’s salt shed—the same issue occurred. I had to pull over again and allow battery to recharge. This is not a complete hybrid, it has a gas engine not sure why the hybrid and gas are not syncing up. Many users on the internet have reported the same issue that I have experienced. Someone needs to investigate this before major injury occurs.

Immediately following routine maintenance performed at an authorized Hyundai dealership, my 2025 Hyundai Hybrid Santa Fe Calligraphy experienced a complete loss of engine oil, which resulted in the engine shutting down while driving on a highway. While traveling at highway speed with my minor daughter, the oil pressure and engine warning lights illuminated, followed by multiple error messages. The vehicle rapidly lost power, and I struggled to safely maneuver it onto the shoulder while high-speed traffic was passing. This created an immediate and life-threatening safety situation, with a real risk of being struck by other vehicles. We were stranded on the roadside for over three hours awaiting a tow, exposed to ongoing traffic danger. The dealership later advised that the incident was caused by a faulty Hyundai-supplied part, not driver error, misuse, or lack of maintenance. The vehicle had only approximately 4,000 miles at the time of failure. A sudden engine shutdown due to oil loss at highway speeds presents a severe risk of collision, injury, or death, especially when it occurs without warning. Given that a Hyundai component is implicated, I am concerned this may represent a broader safety defect affecting other vehicles. This incident caused extreme distress and endangered both myself and my child. I am submitting this complaint so that NHTSA may evaluate whether this issue warrants regulatory review or further investigation.

My 2025 Hyundai Santa Fe Hybrid has recurring powertrain communication failures starting at only 67 miles and continuing at 5,300 and 6,200 miles. Diagnostic trouble codes include U010100 (lost communication with engine control module) and multiple U100xxx codes related to transmission and CAN bus communication failures. These indicate loss of communication between critical control modules. The issue has happened multiple times and remains unresolved. I am concerned this could cause drivability problems, warning lights, or sudden loss of power. This appears to be a system-level defect in the vehicle’s communication network.