21 of the 1,660 complaints about the 2015 Hyundai Sonata are about the driver-assist systems — 1% of everything reported for this model year. Half of the failures with a mileage on record happened before 88,000 miles.
21
Complaints
4
Crashes
0
Fires
1
Injuries
Filed with NHTSA, in their own words.
FORWARD COLLISION AVOIDANCE: WARNINGS
My 2015 Hyundai Sonata has a defective engine. The motor failed unexpectedly even though the car has low usage and has always been maintained properly. I was informed that many Hyundai engines from these years came with manufacturing issues, and mine appears to be one of them.
NHTSA complaint #11702481 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: WARNINGS
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 NHTSA 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.
NHTSA complaint #11660512 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: WARNINGS
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)
NHTSA complaint #11636029 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
Vehicle displayed hybrid warning while moving through an intersection on a highway. The car's engine turned off along with the power steering and brakes. Had the light not been in my favor, I would have been unable to stop on a high speed highway with oncoming traffic.
NHTSA complaint #11548265 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
The car has had multiple issues with the hybrid system. I’ve taken it to the dealership about 4-5 times. They “fix” the issue but a little while later I’m having more hybrid warming issues. This last time I took it to a different dealership, paid for a diagnostic test, and was told my hybrid system was bad but because it was repaired too many times instead of replacing it, it’s no longer covered under warranty. The issue from the last diagnostic test showed the master brake cylinder was faulty, I replaced it but I’m still having the same issue. The mechanic I took it to did their own diagnostic test and it showed there is an issue with the hydraulic booster, high pressure accumulator short term charge. When I searched the issue, I’ve found that many people are having the same issue with the same car/year as mine. I contacted the manufacturer and they are still not willing to fix it even though it is a possible defect in the car.
NHTSA complaint #11543021 — an unverified report by a vehicle owner.
LANE DEPARTURE: BLIND SPOT DETECTION
Rear passenger door will not lock manually or via manufacturer installed causing issues with child safety lock and at high speeds can be opened causing injuries and or death ,Windscreen on panoramic sunroof detaches causing safety hazard
NHTSA complaint #11524597 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: WARNINGS
Rear passenger door will not lock manually or via manufacturer installed causing issues with child safety lock and at high speeds can be opened causing injuries and or death ,Windscreen on panoramic sunroof detaches causing safety hazard
NHTSA complaint #11524597 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
The engine stopped working completely
NHTSA complaint #11508839 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
Engine keeps losing power not sure why & also abs brake system out of nowhere when accelerating in freeway they automatically brake sometimes for safety feature
NHTSA complaint #11506666 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: WARNINGS
Forward collision warning is frequently inaccurately sensing collision even when no other vehicles are on the road. I am now afraid to use adaptive cruise control because I fear sudden breaking especially when merging lanes.
NHTSA complaint #11502058 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
Forward collision warning is frequently inaccurately sensing collision even when no other vehicles are on the road. I am now afraid to use adaptive cruise control because I fear sudden breaking especially when merging lanes.
NHTSA complaint #11502058 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
ABS and Traction Control warning lights came on, then went out the next time I started the vehicle. They then did this a second time. On the third time, they stayed on. Brakes worked fine, and vehicle had plenty of brake fluid. Inspection at dealership revealed left rear wheel speed sensor malfunction. Research discovered that this could cause a braking problem as the issue continued. Dealership verified this is a possibility. Dealership also stated they have had a number of vehicles report this issue; doesn't seem to be related to any particular year.
NHTSA complaint #11469877 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
I had a safety recall on my car for the Smart Junction Box. I took the car to the dealership on March 9th 2022. They updated the software that controlls the Smart Juntion Box. On March 11th 2022 at 6:45am I got in a car accident due to the automatic braking system failure. I run into a Ford F-150 at the stop light. Even the brakes at this point failed to work properly as well. I called the deslership and explained what happened to me and I was told by the technician that there is a possibility that the update of the software that runs the Smart Junction Box has impacted the Smart Cruize Control. He said there is a possibility that the Smart Cruize Control settings have been erased to default so the car needed a new settings. That was something I did not know about. My car has the option where you can choose what distance you want between your car and the car in fromt of you. It goes from one-space car to four-space cars. So according to the technician this may has been the problem.
NHTSA complaint #11459959 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
I had a safety recall on my car for the Smart Junction Box. I took the car to the dealership on March 9th 2022. They updated the software that controlls the Smart Juntion Box. On March 11th 2022 at 6:45am I got in a car accident due to the automatic braking system failure. I run into a Ford F-150 at the stop light. Even the brakes at this point failed to work properly as well. I called the deslership and explained what happened to me and I was told by the technician that there is a possibility that the update of the software that runs the Smart Junction Box has impacted the Smart Cruize Control. He said there is a possibility that the Smart Cruize Control settings have been erased to default so the car needed a new settings. That was something I did not know about. My car has the option where you can choose what distance you want between your car and the car in fromt of you. It goes from one-space car to four-space cars. So according to the technician this may has been the problem.
NHTSA complaint #11459959 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: WARNINGS
I had a safety recall on my car for the Smart Junction Box. I took the car to the dealership on March 9th 2022. They updated the software that controlls the Smart Juntion Box. On March 11th 2022 at 6:45am I got in a car accident due to the automatic braking system failure. I run into a Ford F-150 at the stop light. Even the brakes at this point failed to work properly as well. I called the deslership and explained what happened to me and I was told by the technician that there is a possibility that the update of the software that runs the Smart Junction Box has impacted the Smart Cruize Control. He said there is a possibility that the Smart Cruize Control settings have been erased to default so the car needed a new settings. That was something I did not know about. My car has the option where you can choose what distance you want between your car and the car in fromt of you. It goes from one-space car to four-space cars. So according to the technician this may has been the problem.
NHTSA complaint #11459959 — an unverified report by a vehicle owner.
LANE DEPARTURE: BLIND SPOT DETECTION
The abs and traction lights are illuminated on dash with check bsd system warning on dashboard as well. Seems to be common problem with this car. With these lights on the abs system I disabled. Was told it was speed censor and then it was the bsd sensor in bumper. They told me it was in an accident I should file claim with insurance. Sounds like they don't want to repair something faulty . No abs working could mean crash
NHTSA complaint #11446607 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
MY SCC AN MY LDWS CAME ON AN MY RPM AN SPEEDOMETER GAUGE FLAT LINED ON MY WAY TO WORK GOING 55 TO 60 MPH I PULL OVER AS SOON AS POSSIBLE BECAUSE I WAS ON A HIGHWAY NOT PASSING ANYBODY I TURNED OFF THE CAR AN WAITED A COUPLE MINUTES THINKING IT WAS PROBABLY A GLITCH BECAUSE I JUST GOT MY ENGINE REPLACED FROM THE RECALL NOT TO LONG AGO AN WHEN I WAITED ABOUT 10 TO 15 MIN MY CAR REFUSED TO START AN I COULDN'T TAKE IT OUT OF GEAR AN HAD 5O HAVE IT TOWED TO THE DEALERSHIP
NHTSA complaint #11388947 — an unverified report by a vehicle owner.
LANE DEPARTURE: BLIND SPOT DETECTION
MY SCC AN MY LDWS CAME ON AN MY RPM AN SPEEDOMETER GAUGE FLAT LINED ON MY WAY TO WORK GOING 55 TO 60 MPH I PULL OVER AS SOON AS POSSIBLE BECAUSE I WAS ON A HIGHWAY NOT PASSING ANYBODY I TURNED OFF THE CAR AN WAITED A COUPLE MINUTES THINKING IT WAS PROBABLY A GLITCH BECAUSE I JUST GOT MY ENGINE REPLACED FROM THE RECALL NOT TO LONG AGO AN WHEN I WAITED ABOUT 10 TO 15 MIN MY CAR REFUSED TO START AN I COULDN'T TAKE IT OUT OF GEAR AN HAD 5O HAVE IT TOWED TO THE DEALERSHIP
NHTSA complaint #11388947 — an unverified report by a vehicle owner.
LANE DEPARTURE: WARNING
MY SCC AN MY LDWS CAME ON AN MY RPM AN SPEEDOMETER GAUGE FLAT LINED ON MY WAY TO WORK GOING 55 TO 60 MPH I PULL OVER AS SOON AS POSSIBLE BECAUSE I WAS ON A HIGHWAY NOT PASSING ANYBODY I TURNED OFF THE CAR AN WAITED A COUPLE MINUTES THINKING IT WAS PROBABLY A GLITCH BECAUSE I JUST GOT MY ENGINE REPLACED FROM THE RECALL NOT TO LONG AGO AN WHEN I WAITED ABOUT 10 TO 15 MIN MY CAR REFUSED TO START AN I COULDN'T TAKE IT OUT OF GEAR AN HAD 5O HAVE IT TOWED TO THE DEALERSHIP
NHTSA complaint #11388947 — an unverified report by a vehicle owner.
LANE DEPARTURE: BLIND SPOT DETECTION
I OWN A 2015 HYUNDAI SONATA AND I OWN IT SINCE BEGINNING. ALL OF A SUDDEN THE KEY FEATURES SUCH AS BLIND SPOT DETECTION (BSD), ALONG WITH ANTI-LOCK BRAKING SYSTEM (ABS) AND CAR SKIDDING PREVENTION SYSTEM STOPPED TO WORK IN MY CAR. I CONTACTED HYUNDAI DEALERSHIP (WITH MY CAR CLOCKING ABOUT 62,650 MILES) AND I WAS TOLD THAT SUCH IMPORTANT SAFETY FEATURES ARE NOT COVERED UNDER WARRANTY. WHEN I CONTACTED HYUNDAI USA CORPORATE OFFICE, I WAS TOLD THAT SUCH KEY SAFETY FEATURE CAN GO WRONG ANY TIME WHICH WAS SUCH A SHOCKING NEWS FOR ME AND MY FAMILY. MY CAR DOES NOT DETECT ANY VEHICLE WHICH IS COMING/PASSING THROUGH AT HIGH SPEED, AND THE REAL WORST THING IS THAT IT'S ANTI-LOCK BRAKING SYSTEM (ABS) AND SKIDDING WARNING SYSTEM ARE NOT AT ALL FUNCTIONING WHICH COMPROMISE THE SAFETY OF MY FAMILY. I AM REALLY CONCERNED FOR THE SAFETY OF MY FAMILY AND OTHER PEOPLE TRAVELING IN DIFFERENT CAR AT THE SAME TIME. MY FAMILY'S SAFETY MEANS NOTHING FOR DEALERSHIP OR TP HYUNDAI CORPORATION BUT THEY ARE JUST CONCERNED TO BILL ME AND MY FAMILY HUNDREDS OF DOLLARS FOR THEIR FAULTY PARTS/SAFETY SYSTEM AT THIS PANDEMIC TIME.
NHTSA complaint #11377976 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
WHEN TRYING TO SET MY CRUISE CONTROL A MESSAGE POPS UP ON MY DASH SAYING SCC CONDITIONS NOT MET.
NHTSA complaint #11372927 — an unverified report by a vehicle owner.