Driver assistanceEnginePowertrain (other)
Filed Sep 23, 2026
The primary component failure is within the hybrid powertrain control architecture, specifically involving the transmission control system or internal transmission clutches/modules (TCM/HEV control module). The vehicle utilizes a 6-speed automatic transmission integrated with an electric motor. During highway cruising, the transmission locks into a single gear ratio or a protective "limp mode," resulting in a total loss of normal acceleration despite high engine RPMs. The vehicle and its components are fully intact and available for inspection upon request. My safety and the safety of others were put at severe risk because the sudden, unexpected loss of acceleration occurred while traveling at highway speeds in active traffic. When the transmission locked and power cut out, the vehicle rapidly shed speed and dropped to a hazardous 20-35 mph on a high-speed roadway. This created an immediate, extreme risk of a high-speed rear-end collision from vehicles traveling behind me, forcing me to make defensive lane changes toward the shoulder without normal engine power to navigate safely. This happens without warning no notices or errors pop up when it happens. The issue is intermittent and has been presented to an authorized Hyundai dealership technician multiple times. Because the vehicle often resets its communication modules and temporary limp-mode parameters once the ignition cycle is turned completely off and back on, the dealership technicians have encountered difficulty pulling permanent historical diagnostic trouble codes (DTCs). However, the failure patterns match a widely documented, repeating issue among 2025 Santa Fe Hybrid owners regarding HEV torque calculation or loose engine wiring harness pin tension
- NHTSA ID
- 11766539
- Incident
- Sep 23, 2026
ElectricalEnginePowertrain (other)
Filed Sep 19, 2026
While driving on a highway at approximately 60 MPH, the vehicle abruptly suffered a catastrophic loss of power and entered "Limp Mode," creating a severe safety hazard on the roadway. The vehicle was safely maneuvered and pulled over to the side of the road. Upon shutting the vehicle down and attempting to restart it after a few minutes, the powertrain completely failed to engage, refusing to shift into either Drive or Reverse. The vehicle became entirely disabled and required a flatbed tow to the dealership. Dashboard Warning Messages: - "Transmission Control System" - "Check Hybrid System" Diagnostic Trouble Codes (DTCs): - P177700 (Transmission / Hybrid Powertrain Control Malfunction) - P178400 (Transmission Control System / Electric Oil Pump or Actuator Circuit Fault)
- NHTSA ID
- 11765583
- Incident
- Sep 2, 2026
ElectricalEngineFuel system
Filed Sep 14, 2026
**What component or system failed, and is it available for inspection?** The vehicle's electrical/power system failed, causing a complete loss of power while driving. This is the fourth occurrence of this failure. The vehicle is currently at the Hyundai dealership and available for inspection. **How was your safety or the safety of others put at risk?** The power failure occurred while driving on a busy road. The driver struggled to safely maneuver the vehicle (executing a U-turn) to get out of traffic and reach a safe location. The vehicle had to be towed as a result. **Has the problem been reproduced or confirmed by a dealer or independent service center?** The vehicle has been brought to the Hyundai dealership for this same issue four times. As of the most recent update, the dealership has not been able to identify the root cause or confirm a fix. **Has the vehicle or component been inspected by the manufacturer, police, insurance representatives, or others?** The vehicle is currently with the Hyundai dealership (manufacturer-affiliated) for the fourth time for inspection related to this issue. No inspection by police or insurance has been reported. **Were there any warning lamps, messages, or other symptoms prior to the failure, and when did they first appear?** There were no warning lamps, messages, or other symptoms prior to the failure. Warning lamps/messages appeared only after the vehicle lost power.
- NHTSA ID
- 11764110
- Incident
- Jun 9, 2026
The car suddenly loses acceleration; the engine still runs and revs to ~3,000 RPM. The car can't drive over 35mph; no check engine light at all. The dealer said a high-pressure fuel pump caused it and replaced it under warranty; after 3 days, the same problem happened again. This is extremely dangerous if the vehicle is on a highway and suddenly loses acceleration. This could be fatal for the driver and other vehicles around it.
- NHTSA ID
- 11763033
- Incident
- Aug 27, 2026
Driver assistanceEnginePowertrain (other)
Filed Sep 4, 2026
First Incident – XXX Weekend ([XXX]) Accelerating at an on-ramp to a major highway (I-37S) in [XXX], vehicle suddenly lost power. Speed dropped from 60 mph to 45 mph, then 28 mph, in a 65 mph zone during rush hour traffic. No apparent cause: had ¾ tank of fuel, a clean maintenance history, and no prior issues. Managed to reach the shoulder and, after several minutes, able to exit the highway. Vehicle would not accelerate above 35–45 mph and stayed around 30mph, and the hybrid battery showed less than 25% charge. Notified Red McCombs Hyundai (original seller). When a loaner vehicle became available, we brought the Santa Fe in. After a week, the dealership stated they could not duplicate the problem and returned the vehicle to us. Second Incident – XXX ([XXX]) On a planned trip from [XXX] to [XXX], again experienced a sudden and severe loss of power. While merging onto I‑10W, in [XXX], the vehicle speed dropped from 80 mph to 60, then 50, then 38 mph. Able to avoid a collision because of an unusually wide median where I could safely stop. Used GPS to find a local Hyundai dealer - Casa Hyundai of [XXX] - and drove there, using surface roads only. Turned vehicle in for maintenance and continued trip using a loaner vehicle. Casa Hyundai reported, days later, that despite logged error messages indicating problem with hybrid system and advising user to immediately stop, they were unable to isolate problem. Third Incident – XXX (Unknown location in [XXX]) Entering I-10E after fuel stop (80mph zone) and accelerating hard on a slight incline, again experienced sudden loss of power, slowing to less than 40 mph. Drove on shoulder for two miles to next exit 284 and stopped w/motor running to recharge. No error codes or warnings displayed on dash. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- NHTSA ID
- 11762194
- Incident
- Jul 4, 2026
EngineFuel systemPowertrain (other)
Filed Sep 2, 2026
While driving, the vehicle suddenly lost motive power on the highway and would not accelerate beyond approximately 20 mph despite accelerator input. There were no warning lights or check-engine light. The condition created a safety hazard because the vehicle could not maintain normal traffic speed. Hyundai dealer has been unable to determine the cause on other vehicles with the same problem, and was trying to discourage me from reporting this. They also said that they'd keep the car for 3 days, and likely return it with no diagnosis, so do I really want to go through this? They seemed unconcerned that this is a very dangerous issue in a highway.
- NHTSA ID
- 11761734
- Incident
- Sep 2, 2026
Driver assistanceEngineFuel system
Filed Aug 28, 2026
When traveling home from work 8/27/26, my cruise control shut off and my car immediately went into “limp” mode. This almost caused me to get into an accident with a tractor trailer, in which, I may not have survived. Immediately pulled over and tried to find out what had caused this and how to get it fixed. Nothing worked to get it out of “limp” mode. There were no warning lights or messages, except LV3. Which was a completely different issue. This issue I was able to correct. Tried fixing the “limp” mode issue by doing as told by Google AI, turn car off, lock door with key fob, waiting 10-15 minutes for computer to reset. NOTHING. Also tried checking to see if there was a battery dump, in which this case would have been the fuel system not communicating with the hybrid battery system, NOTHING. I do have an appt with the dealership on 9/2/26 to have this looked at and inspected. I have not tried to start and or drive the car again, since. Do not want to be blamed by the dealership or manufacturer, that I did something wrong or caused more issues.
- NHTSA ID
- 11760351
- Incident
- Aug 27, 2026
ElectricalEngine
Filed Aug 25, 2026
While driving in the evening around 9:00 pm with AC on crash detection lights came on along with other emergency dashboard lights . Speed was limited to 23 miles per hour .
- NHTSA ID
- 11759322
- Incident
- Aug 20, 2026
BrakesEngine
Filed Aug 24, 2026
My vehicle randomly slows it self down while driving. I would be pressing the gas and the car would voluntarily slow down on its own with no warning. This problem can lead to plenty of accidents due to me or any other driver around me being unaware when my vehicle will brake on its own. The problem has been confirmed by Hyundai Patterson of Tyler, Texas and they have worked on my car twice to fix the issue and it still hasn't been fixed. The issue started about a month ago and when the incidents would occur in the beginning their would be no warning lights on my vehicle’s dash. As of recently there maybe a check engine light that will pop up when the incident occurs. It's a hit or miss.
- NHTSA ID
- 11759187
- Incident
- Jul 31, 2026
Driver assistanceEngineFuel system
Filed Aug 20, 2026
sudden loss of propulsion / limp mode, particularly under load or at highway speeds.
- NHTSA ID
- 11758162
- Incident
- Aug 11, 2026
ElectricalEngineFuel system
Filed Jul 27, 2026
1. The SUV experiences complete power loss and goes into limp mode. Have been in nearly 3 accidents on highways with a vehicle that goes from 65 to 35 with no warning and then cannot accelerate or gain speed. 2. Battery, out of no where, goes from 3/4 full to 1 or 2 bars. 3. Extreme shaking of the vehicle while driving and at rest. 4. Vehicle is less than a year old and has been in for the same issue 4x. Currently with dealership since 6 July with no communication despite calls and in-person visits. 5. Loaner not provided despite car being under warranty and brand new.
- NHTSA ID
- 11752967
- Incident
- Feb 9, 2026
EnginePowertrain (other)
Filed Jul 21, 2026
The vehicle has gone into a limp mode unexpectedly while driving on the highway at 60+ mph. The car immediately stopped driving and went into limp mode and cannot go over 30 mph. It was taken to a service dealer. They could not replicate the problem, therefore the vehicle was given back as undiagnosed. This next incident occurred and almost caused an accident, and that was on, again driving on the beltway around Columbus, OH. The car went from 70 mph to 30 mph. The vehicle stayed at 25 to 30 mph the entire time. Could not get it to do anything else. Drove cautiously on the side of the road and got to the dealership after driving 30 minutes at 25 mph. Dealership ended up saying the transmission needed replaced. It has been at the dealer for 3 weeks waiting on a transmission
- NHTSA ID
- 11751764
- Incident
- Jun 22, 2026
Driver assistanceEngine
Filed Jun 21, 2026
The car went from 70 miles an hour to 25 miles an hour all of a sudden on the highway and then would not allow to accelerate afterwards. Battery stopped charging and we had to stop it multiple times to get it to continue to drive no faults or issue on the dashboard.
- NHTSA ID
- 11745451
- Incident
- Jun 21, 2026
The vehicle has gone into a limp mode unexpectedly while driving on the highway at 60+ mph. The first issue was on May 13, 2026. The car immediately stopped driving and went into limp mode and cannot go over 30 mph. It was taken to a service dealer. They could not replicate the problem, therefore the vehicle was given back as undiagnosed. This next incident occurred and almost caused an accident, and that was on June 3, 2026, again driving on the beltway around Maryland. The car went from 70 mph to 30 mph. The vehicle stayed at 25 to 30 mph the entire time. Could not get it to do anything else. Drove cautiously on the side of the road and got to the dealership after driving 30 minutes at 25 mph.
- NHTSA ID
- 11741876
- Incident
- Jun 3, 2026
Sudden loss of power while driving on the interstate (65 MPH) , car would no longer accelerate and slowed down to ~10 MPH. Had to merge onto emergency lane, car struggled to power over 30 MPH. Warning light came up to "Park with engine On to charge battery". Parked car and restarted car and still did not resolve issue. Had to switch the car into "Sport" mode to drive home.
- NHTSA ID
- 11741466
- Incident
- Jun 1, 2026
EngineFuel system
Filed Jun 1, 2026
While driving on the freeway at approx 65mph, the car suddenly starting de-celerating and forced me to pull over to emergency shoulder/lane and try to determine the cause. The car is a "Hybrid" and the dashboard stated to put car in Park and Idle the Engine over 2000rpm to charge up the Battery. ( i still don't know which Battery they were speaking of...Engine Battery or Hybrid Battery) I sat there Idling the Engine for 15 minutes and slowly proceeded to get off the freeway and limped the car back to my home. I then called my selling Hyundai Dealer, as the car was still in warranty, and told them of my sudden problem and asking them what could it be??? They said they did not know until they saw the car and tested it with their computer equipment...please have it towed into their shop. So i did and 2 days later they called to say..NO Computer Codes showed any problem. They could not duplicate problem. I said ..."look on the internet...many people have reported sudden lack of power and limp mode activation....all pointing to the High Pressure GDI Fuel Pump Assy failure". Dealer said ..Oh..thanks we will look into that. 5 hours later Dealer called and said I was right, we replaced the Fuel Pump and come pick up the car. 4 months later and 6,000 miles later car is performing normally. I felt compelled to come forward to discuss this part failure as this incident on the freeway could have turned into a tragedy. Thank you
- NHTSA ID
- 11741374
- Incident
- Jan 14, 2026
EngineFuel systemPowertrain (other)
Filed May 27, 2026
My 2025 Hyundai Santa Fe Hybrid AWD was serviced under warranty on 4/22/2026 for a driveability concern after experiencing a loss of power while driving. The service history shows part HY35326-2M500 was replaced. On or about 5/25/2026, the same issue occurred again while driving at highway speed. The vehicle suddenly lost motive power and dropped from approximately 70 mph to approximately 30 to 40 mph, creating a serious safety risk because the vehicle could not maintain speed with surrounding highway traffic. No warning lamps, dashboard messages, or diagnostic codes appeared during the failure. The vehicle is currently at a Hyundai dealership for inspection and repair for the repeat issue and should be available for inspection upon request. The prior dealer record appears to describe the issue generally as a “driveability concern,” but the current repair diagnosis and full repair notes are still pending. It is unknown whether the dealer has reproduced or confirmed the failure during the current visit. I am reporting this as a sudden loss of motive power at highway speed involving the fuel/propulsion system, engine, and/or powertrain.
- NHTSA ID
- 11740281
- Incident
- Apr 22, 2026
ElectricalEnginePowertrain (other)
Filed May 10, 2026
Driving home from church this morning, the vehicle experiences a sudden loss of power and the car went into “limp mode”. Even the pedal floored and the engine rpms high, the car would barely go about 25 or 30 mph. A message from the dash board told me to pull over and leave the engine running to charge the EV batteries. The batteries would charge enough for what I thought would get me home but quickly drained leaving repeat the action until I could limp the six miles home with flashers on and cars passing me to get around. No warning lights and no indication there was a problem until it happened leaving me baffled and frustrated. I was just thankful that I wasn’t going faster when it happened. If I had been going faster when this happened, it could have created a major accident. Dangerous! Since this happened on Sunday, the dealer wasn’t open. I hope to get it to the dealer tomorrow to find out what is going on and how to fix it. The car has only 14850 miles on it.
- NHTSA ID
- 11736908
- Incident
- May 10, 2026
ElectricalEnginePowertrain (other)
Filed May 6, 2026
The contact owns a 2025 Hyundai Santa Fe. The contact stated that while driving approximately 65 MPH, the vehicle unexpectedly decelerated to 25 MPH with a “Vehicle Will Shut Down” warning message displayed. The contact stated that the engine then began to shut down, and although the accelerator pedal was depressed, the vehicle failed to accelerate and stalled. The failure occurred on multiple occasions, requiring the vehicle to be towed each time. The vehicle was towed to the dealer; the vehicle was not diagnosed or repaired and the contact was informed that the failure could not be duplicated. The manufacturer was made aware of the failure and multiple cases were opened, The failure mileage was approximately 3,300.
- NHTSA ID
- 11736009
- Incident
- May 6, 2026
- Mileage
- 3,300 mi
ElectricalEngineFuel system
Filed Apr 23, 2026
Since February 2026 I have had daily incidents of the hybrid system error where the vehicle is only relying on the hybrid battery to move. I've had a few near miss accidents as my car crawls through an intersection. Was almost rear-end after leaving a stop sign and the hybrid system error popped up and the car doesn't accelerate. In order to temporarily fix the system, the car must be shut off and restarted. There is not always a safe place to be pulled over to perform this shut down. It is a driving hazard and not safe to drive. It has been to the shop now a 3rd time with no resolution. I have reached out direct to Hyundai Corporation with my concerns and they have documentation. The car is a 2025 model and has less than 5,000 miles. I fear a serious accident from this system error and Hyundai needs to resolve ASAP.
- NHTSA ID
- 11733192
- Incident
- Feb 13, 2026
EngineFuel systemPowertrain (other)
Filed Apr 13, 2026
I had stopped and put gas in for a full tank. Pulled out onto the Hwy heading towards Houston TX and was accelerating up to speed limit of 50MPH when the warning on the instrument panel displayed HYBRID SYSTEMS DISABLED pull over and stop immediately. Which I did, but I could not accelerate and was losing speed in traffic. I got safely parked and turned the vehicle off. I let the car sit for a few minutes and started it back up. All warnings were gone and the vehicle has performed normally since up to the current mileage of 9374. I took the vehicle to Hyundai today, 4/13/2026 and they hooked it up to the diagnostic system and it showed NOTHING.
- NHTSA ID
- 11730952
- Incident
- Apr 9, 2026
Driver assistanceEngine
Filed Mar 28, 2026
Gas Motor is not engaging to assist electric drivetrain on a hybrid AWD 2025 Santa Fe. This resulted in a dangerous situation crossing a busy road from a stop sign. The Santa Fe rolled into the intersection at the drivers request, but did not accelerate normally (only to a maximum of a few miles per hour) and felt like an eternity to cross the road. Fortunately oncoming drivers from left and right were paying attention and slowed down and in one case honked aggressively to point out we driving badly. Pulling over to the side of the road, turning the vehicle off and then back on again has sometimes made it run normally, but we limited our trips at that point to first getting safely home and then delivering it to the dealer. The 20 mile drive to the dealer required pulling over twice to reset the vehicle so the electric motor would assist. We have had repeated warnings from the onboard system including "Follow up checks required - Engine Management System" and "There may be a problem with the engine management system Contact your Dealer". I will note that we have 11,000 miles and 11 months experience with the vehicle with NO problems. It may not be relevant, but these new faults began 2 days routine service for oil and tire rotation when recall was performed including ECU Software Update for Recall 25-01-028-1. Dealer is uncertain of problem and referring with outside tech assistance from Hyundai but we were told to expect 2 weeks for parts and repair and uncertainty as to whether that would fix it. In the meantime a vehicle with unreliable acceleration and top speed is unsafe and parked. I do note on this NHTSA website 2025 HYUNDAI SANTA FE HYBRID SUV AWD that there are 47 Complaints. 9 relating to this problem all beginning October 2025 and none prior back to the first post of Nov 2024 for this model. Complaints similar to this for engine management and speed and power loss account for 50% of complaints for this vehicle on the NHSTA website since October 2025.
- NHTSA ID
- 11727705
- Incident
- Mar 20, 2026
EngineFuel systemPowertrain (other)
Filed Mar 25, 2026
Vehicle experienced a loss of acceleration while driving. When pressing the accelerator, engine RPM increased significantly but the vehicle did not increase speed. The vehicle felt as though it was stuck in one gear and would not upshift or downshift. The issue was most noticeable while driving uphill, where the vehicle was unable to maintain speed despite full throttle input. This created a safety concern as the vehicle could not accelerate normally in traffic conditions. The problem has been progressively worsening over time. Initially there were mild symptoms, but it has become more severe and frequent, culminating in a near-complete inability to accelerate under load. No warning lights or messages were observed prior to or during the failure (if that’s true—adjust if needed). Vehicle has approximately 28,000 miles. The vehicle is currently at a dealership for inspection and diagnosis, but the issue has not yet been confirmed or resolved at the time of this report.
- NHTSA ID
- 11726897
- Incident
- Mar 24, 2026
Driver assistanceEngineFuel system
Filed Mar 23, 2026
Vehicle would not accelerate in high speed zone.
- NHTSA ID
- 11726542
- Incident
- Mar 23, 2026
ElectricalEngineFuel system
Filed Jan 31, 2026
While driving at highway speeds (59–75 mph), the vehicle suddenly lost propulsion power and entered a reduced-speed “limp mode,” rapidly decelerating and creating a dangerous traffic situation. The dashboard displayed a “Hybrid Power Control Unit” warning along with audible alarms. During the second incident, the vehicle failed to shut off when the engine stop button was pressed. Multiple adult witnesses were in the vehicle on each dangerous traffic situation.
- NHTSA ID
- 11714689
- Incident
- Nov 8, 2025
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.