Vehicle 1 operating normally in traffic on [XXX] in Westfield MA. Operator 1 notices alert on dashboard. As Operator 1 looks down briefly and returns eyes immediately to the road, she sees Vehicle 2 braking to slow or stop. Operator 1 depresses brakes, but vehicle does not slow as it usually does, nor does Automatic Emergency Braking engage as it always has in the past. Front of Vehicle 1 makes contact with rear of Vehicle 2. Dashcam footage appears like brakes did not activate at all, either manually or automatically. Vehicle 1 airbags deploy. Westfield Police respond, as well as Westfield Fire, who cut the battery cable. Vehicle towed to Interstate Towing, Inc. Yard 5, 20 Clifton St, Westfield, Ma 01085. (413) 593-1900 interstatetowing.com. Owner 1 viewed vehicle at tow yard, and noted that the battery was completely melted, with only portions of the plastic casing along with internal plates visible. Much of the plastic and rubber components immediately adjacent to battery location were melted and deformed. As a layperson, it almost appears as though the battery was in the process of shorting out just prior to the collision, possibly rendering many of the safety systems inoperable. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Hampden, MA, USA

As soon as I start to press on my brakes the vehicle starts violently pulsating and locks up. Took the dealership they said my rotors and brakes were fine and we're unable to give any reason for this. Without brakes I cannot stop my vehicle and it seems like a faulty ABS but no light on dashboard. The engine consumes nearly 5.2 qts of oil in 1000 miles. Being this is not normal I have no idea I was running out of oil as soon as I was changing it which could have led to my entire engine stalling out and causing me to wreck. It's putting my life as well as other people's on the roads and danger

- Lewisburg, TN, USA

The contact owns a 2018 Hyundai Sonata. The contact stated while their vehicle was parked, starting the ignition, and attempted to make 3 point turn exiting out of their driveway, the vehicle accelerated on its own and went over their curb into their neighbor yard. The contact stated they depressed the brake pedal to stop the vehicle, however, the vehicle continued to accelerate at a slow speed before finally coming to a stop. The contact was able to reverse and exit out of their neighbor's yard and continue to drive to their destination, however, the failure intermittently occurred several times. The contact took the vehicle to a local dealer who inspected the vehicle but could not diagnose the cause of the failure. The contact went to another local dealership (Cars Unlimited Of Suffolk LLC 2096 NY-112, Medford, New York 11763 Phone: (631) 758-2200) but the dealer was not able to duplicate the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 8,896 miles.

- Coram, NY, USA

Rough vibration slowly coming up steering when braking to stop. Could be rotors or tires. Started a few months ago.

- Toms River, NJ, USA

2018 Hyundai Sonata. Consumer writes in regards to rusty brakes. The consumer stated the vehicle had issues start during cold weather. It would take about 15 minutes or longer for the vehicle to turn on. The battery needed to be replaced prematurely.

- Mission, TX, USA

Since day of delivery two years ago, the aeb system has malfunctioned in that while driving vehicle on any road type, the brakes come on with no warning or reason, have almost been rear ended three times.dealer has never found anything wrong and insists the system functions as designed. The radar or camera systems have to have a defect. Toyota and Honda have had this issue but made efforts to correct either by recalls or service bulletins. Pedestrian detection has also never worked on this vehicle..

- Shrewsbury, MA, USA

"multiple warning lights are coming on the dash for ABS failure."cause: 5891R00 hydraulic module assembly replaced. "scan test codes C1741, C2402, C1360 diag system. Line case number 2019080600434 perform voltage and ground test per tech line found ABS hydraulic unit internal failure, replaced ABS hydraulic unit, perform all calibrations and variant coding clear codes, reset adaptives. Problems of yellow light coming on on dash was during accelerations and turning cruise control

- Keller, TX, USA

I own this 2019 Sonata since 1/16/19. Was runing good at the first. But couple times start showing the engine light for seconds. But on April Sunday 14 2019 my car shows the engine light and the tire control stabilizer at the same time then the car start shaking lossing speed, the brakes getting hard and power steering.. lucky I went at 10mph to 15mph.the vehicle will be placed in a temporary engine protection mode with reduced power and acceleration. No speed no acceleration then I park in a parking lot for towing at the nearest Hyundai dealership. Technitia found code( P0638 ) active code and (P211935002A00 throttle body carbon cleaning- adjustment and found rubber grommet stuck in the throttle body roved grommet. This cause trouble with the intake and injectors making the car limp and state in protection mode. I have lucky I wasn't in the freeway at 55,60 to 65 mph. O can be a different risk and dangerous for me and others drivers. Please take this note seriously before something worse can happen to others drivers. Thank you so much.

- Waterbury, CT, USA

The contact owned a 2018 Hyundai Sonata. While driving approximately 5 mph, the vehicle independently accelerated. The contact depressed the brake pedal, but it failed to slow down or stop the vehicle. The vehicle crashed into a palm tree. An incident report was filed, but not a police report due to the fact that there was no immediate injury. The contact suffered a sore neck and a possible whiplash. The vehicle was towed to an independent facility. Kearney mesa Hyundai (4797 convoy St, san diego, ca 92111, (858) 278-7100) was contacted and a voice message was left. The manufacturer was not contacted. The cause of the failure was not determined. The approximate failure mileage was 500. Consumer stated brake pedal was pushed multiple times and she did seek medical attention.

- Chula Vista, CA, USA

I had stopped my vehicle, putting emergency brake on, but still in drive. I stepped out of the car and it began to move forward on its own and I was not able to get back into the vehicle. It traveled quite a distance before running into some inanimate that caused it to stop. It was in a driveway behinds buildings and did eventually cross over a side street before stopping. I don't see why the emergency brake did not hold, even though not in park?

- Charlotte, NC, USA

The contact owns a 2018 Hyundai Sonata. While operating the vehicle, the automatic emergency braking system malfunctioned. On several occasions, the vehicle failed to automatically stop when a second vehicle was present. The failure occurred while driving in reverse and while driving at highway speeds with the cruise control activated. The vehicle was taken to napleton Hyundai glenview (1620 waukegan rd., glenview, il) and the contact was informed that the failure was normal. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 400. Consumer stated braking works when car has cruise control activated, when relying in "aeb" nothing happens. Vehicle purchase date should be on or before incident date updated 9/21/18

- Evanston, IL, USA