Which parts fail
Components named in complaints (automatic emergency braking, adaptive cruise, lane keeping, backup camera).
Owner reports
Selected complaints filed with NHTSA by 2021 Hyundai Elantra owners, lightly cleaned up (personal details are redacted by NHTSA).
My father was involved in a car crash, front end into a wall. Apparently, the front end collison warning did not sound and the auto braking system never engaged. Prior to the accident, the front end collsion warning would come on intermittently, but the dealer checked it out and stated it was working normally (San Bruno Hyundai). AFter the collision repair, the warning light comes on and the car has been at Bakersfield Hyundai now for over a week, but they can't find anything wrong with the warning system, but the system does not function (no warning of collision and auto braking does not engage). Our accident total was $10,000, lucky, no one was seriously injured.
I am filing a complaint regarding a safety recall repair for my vehicle that is not being handled in a timely or reasonable manner by an authorized dealership Delray Hyundai 655 NE Sixth Ave, Delray Beach. Vehicle Information: 2021 Hyundai Elantra SE VIN: [redacted] Recall Information: NHTSA Recall #24V879000 Recall #271 - Backup Camera Inspection/Replacement This recall involves a failure of the backup camera system, which directly impacts visibility while reversing and poses a safety risk. The manufacturer has indicated that a remedy is available; however, the dealership I contacted is refusing to perform recall repairs on weekends and is only offering an appointment more than a month out (scheduled for May 4th). Given that this is a safety-related recall affecting rear visibility, this delay is unreasonable and places me at continued risk while operating the vehicle. …
The forward collision warning stopped working several months ago. We gave the (leased) car to the dealer for repairs after 4 weeks of waiting (parts, etc.) We were told the car was fixed and ready for pick-up. I drove it from Baltimore to DC for a meeting and on several occassions when car stopped abruptly in front of me on the highway it did not give a warning, when I tried using cruise control, it would not engage because the conditions for doing so had not been met - same message I had when foward collision was not working. It's pretty clear that this was not fixed and instead they must have changed the messaging so that it does not appear as a warning when you start the car. …
In the middle of crossing the Verrazzano Narrows Bridge in New York City, the forward collision warning came on and the braking system automatically engaged REPEATEDLY. I was traveling about 30 MPH and had about 4 car lengths between my car and the one in front. The system kept engaging no matter how much room I put between myself and the car in front of me, and as I was in the middle lane of a bridge in heavy traffic I could not pull over. I always keep a good distance in front when driving, but because of the system inappropriately engaging I almost got rear-ended about four times. I was terrified and this continued to happen until I got off the bridge. I use my car mainly on the weekend, and also travel this bridge almost every weekend and this was the first time this happened but it was terrifying and EXTREMELY DANGEROUS!!!!
My car has two warning lights on my dashboard. First one is Check Foward Safety system. Second one is Check Smart Cruise Control System. Both of them turned on when I was driving in the middle of a highway. These warning lights activated out of the blue, without any unusual circumstances.I cannot use my smart cruise control system and the car is not able to alert me about forward collision. This issue has already been addressed through a recall for my vehicle's model and year in Korea. My vehicle was produced in Korea and was imported to the United States; however, Hyundai has not issued a recall regarding the same problem in the United States. This is a safety concern, and Hyundai should repair it free of charge, and the company should compensate customers who have already undergone repairs for the repair costs.
Driving on highway, dashboard reported "Check Forward Safety System" and "Check Smart Cruise Control System". The car then disabled both while I was driving. This has happened 6 times to me. The first time I brought it to dealer and they stated it was a calibration problem. They reset it and I had no problems for a while. The problem has occurred 5 times more and will stay on for about a week or so and then just go away. It works again and then occurs again. So, it is intermittent and recurring. Each time the diagnostic code reported by the software to my phone is C162078. I see the 2018 Kona had the same exact problem and a software update TSB was put out there. ( https: [redacted] )
One day I was on the highway driving and the front collusion safety warning appeared. I thought the warning went off because the sensor was dirty due to dead bugs. However, I pulled over and the sensor did not appear dirty. After awhile the sensor went off on its own. Then a few weeks late the front collusion safety warning appeared again while I was driving on the highway. The warning has not fixed itself. I cannot use my cruise control. I took it to the Hyundai dealership and they told the me senor is off alignment and it will cost $500 to repair because they have to remove the entire bumper. I have seen on Hyundai forums this is a common problem.
When driving at 55MPH with cruise control on, the car suddenly accelerated to 75MPH, this happened on the open road and was able to keep under control. Auto has less than 10,000 miles. I will be contacting Hyundai customer service for a case number on this incident. First indication of a problem was cruise control, auto braking failed iin June of 2023. This follows a replacement of defective front radar unit by Hyundai which was replaced at 8295 miles on July 26, 2023. This problem first occurred in late June/early July of 2023. There was no warning.
vehicle only has 14k miles and is showing an error message for "check forward safety system" and "check smart cruise control system" after some research found this is a very common issue with multiple Elantra's where the front radar goes bad causing safety systems such as automatic braking/acceleration, and cruise control to not work. this is a big safety issue that has been reported by many drivers. the error happened going a steady 40mph with no other cars around on an open road. nothing was hit the radar just suddenly failed
Several times, including yesterday, my forward collision avoidance engaged by braking suddenly and strongly and INAPPROPRIATELY, almost causing me to be rear-ended. I was nowhere near the car in front of me, and fortunately due to traffic was traveling below the speed limit. This seems to happen whenever there is an overpass above the road. I have reported this to Hyundai, and they don't seem very concerned. Very dangerous. I would think there could be a software or sensor update that can correct this situation.
Related recalls
Back over prevention › Sensing system › Camera
Hyundai Motor America (Hyundai) is recalling certain 2021-2022 Santa Fe, Santa Fe HEV, Elantra, Elantra HEV and 2022 Elantra N and Santa Fe PHEV vehicles. Due to a damaged printed circuit board, the rearview camera image may fail to display.
Remedy: Dealers will replace the rearview camera, free of charge. Owner notification letters were mailed January 14, 2025. Owners may contact Hyundai customer service at 1-855-371-9460. Hyundai's number for this recall is 271.
Collision Avoidance complaints in other Elantra years
Frequently asked questions
How common are collision avoidance problems on the 2021 Hyundai Elantra?
NHTSA has 36 complaints about the driver assistance of the 2021 Hyundai Elantra, 27% of the model year's 132 complaints. The component named most often is warnings (30 mentions).
Is there a recall for 2021 Hyundai Elantra collision avoidance problems?
Yes — NHTSA recall 24V-879 (camera, Nov 21, 2024). Recall repairs are free at authorized dealers.
Is it dangerous?
Owners linked 1 crash, 0 fires and 0 injuries to driver assistance problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.