2021 Hyundai Elantra Electrical Problems

Your engine is shutting off unexpectedly while driving, even when the automatic stop-and-go feature is turned off. This has been happening occasionally but is becoming more frequent, and it's occurred even on the freeway. When it happens, you get a message telling you to shift into park or neutral and restart the engine manually, which creates a dangerous situation since other drivers don't expect your car to suddenly lose power. The fix will likely involve diagnosing the electrical system and engine control computer to identify why the engine is cutting out.

Your daytime and nighttime running lights, high beams, turn signals, and windshield wipers are turning on and off randomly or not working at all. This problem started in November 2025, and your dealer identified a faulty multifunction switch as the cause. While Hyundai initially covered it under warranty, the repair may no longer be covered depending on your warranty status.

Your 2021 Elantra has experienced multiple electrical problems and seat belt issues since purchase, including rear electrical failures, horn malfunctions, and blower motor replacements. The dealership previously cleared your front driver's seat belt as acceptable, but it's still not working properly and now they're refusing to repair it under warranty, citing your mileage over 60,000 miles. They're quoting $1,500 to fix the seat belt and $600 for rear electrical rewiring—issues you've reported for years. Fixing this will likely require seat belt assembly replacement and complete electrical system diagnosis and rewiring of the rear circuits.

You discovered that your car's odometer showed different mileage at different times after purchase from the dealer. When you bought the 2021 Hyundai Elantra, the odometer read 51,192 miles, but when you received the vehicle, it showed 50,310 miles — a discrepancy of 882 miles. This suggests a possible odometer malfunction or tampering that should be addressed immediately with the dealer.

Your car makes a constant sound like water flowing through the front of the vehicle, along with engine ticking and loud rattling noises that you can hear from inside the cabin. This issue has persisted for over a year despite multiple service visits without resolution. The problem likely involves either a coolant circulation issue, air in the cooling system, or internal engine noise that requires diagnostic inspection and potentially cooling system flushing or engine component repair.

Your backup camera doesn't work reliably and the problem is getting worse over time. Sometimes the screen appears partially on and off instead of showing the full camera view. You'll need to have the camera system inspected and likely replaced to restore normal function.

The reverse camera does not work

Back up Camera. When reversing cannot see out back window do to incline of glass making hard to reverse. The problem has not been reproduced or confirmed by a dealer or independent service center. The vehicle or component has not been inspected by the manufacturer, police, insurance representatives or others. There was not any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear.

I am writing to file a formal complaint regarding a significant safety issue with my vehicle’s backup camera system. The backup camera consistently malfunctions, displaying glitchy images with distorted lines across the screen. This issue renders the camera essentially unusable, as it fails to provide a clear view of the area behind the vehicle, posing a serious safety hazard. This malfunction directly impacts my ability to safely reverse, especially in crowded areas where visibility is crucial. The camera’s unreliability puts pedestrians and other drivers at risk, as I am unable to fully ensure that my path is clear when reversing. I strongly believe this defect poses a significant safety concern that needs to be addressed by the manufacturer. I request that the NHTSA investigate this issue and take appropriate action to ensure that this problem is resolved for myself and the many other affected vehicle owners. Thank you for your attention to this matter.

Rear backup camera suddenly stopped working and when in reverse the sensors kick in and breaks the vehicle when there's no object or vehicle behind. Also the code for the backup sensor came up but dealer didn't do anything.

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.

Since last year around 55k miles, my backup camera has stoped working. The first incident happened as I was about to back out of my garage. I opened the garage door and put my car into reverse. As I looked down at the screen and began to back up, I realized the screen showed me an image of a closed garage door ever though the door was open. Almost as if it had taken a screenshot or froze. The second occurrence was similar except it was when I was parking in a job site parking lot. When I put my car in reverse to park, what came on my screen was the image of the highway about 15 minutes prior. I’ve had several experiences like this where the backup camera freezes, has static-like lines all over the screen, discoloration, or delayed effects. This is dangerous because if someone is looking down at the screen and doesn’t realize the backup camera is giving an incorrect output, this can result in an accident (whether it be a single car or multiple car accident). This is because you can end up hitting something/someone if you get delayed feedback on the camera and don’t realize.

Back up camera doesn’t work. When put in reverse the screen is static and when you press the back up camera button it won’t turn on

The contact owned a 2021 Hyundai Elantra. The contact stated that the vehicle was parked unattended. Approximately thirteen hours later, he was notified by the fire department that the vehicle had caught fire. A police report was filed. There were no reported injuries. The vehicle was parked where the fire occurred. The local dealer was contacted but the vehicle was not diagnosed or repaired. The vehicle was towed to an impound lot and later the contact's insurance provider declared the vehicle a total loss, the cause was assumed to be electrical. The manufacturer was contacted but no additional assistance was provided. The failure mileage was approximately 24,000.

I have had to get the horn replaced on my ELANTRA six times the horn goes out and this can be a very big safety hazard as it has caused people to almost hit me because they didn’t see me and my horn wasn’t working to alert them this needs to be addressed as soon as possible as this could cause someone to lose their life in the wrong instance

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.

My car has 76,000 miles on it fully maintained and recorded at hyundai dealerships. One day I’m driving and a check engine light pops up the same day I get it taken in to have it diagnosed, few hours go by I get a call they tell me that the Integrated thermal management module on my car has burnt out. I was surprised because my car is fairly new I asked them how could it prematurely fail they could not give me answer and they told me I would have to pay out of pocket for it and I did. They advised me that I should not drive the car as it could pose severe risk to engine failure as coolant is connected to the part in question. So I left my car there and they ordered a new part and it got fixed the very next day, it was ready for me to pick up. I’m frustrated because I’m not the only one who had this problem and warranty did not cover Hyundai did not want to work with me to resolve my issue and as a result it costed me money and time. I’m not the only one who has this problem but is it really safe for my car to have this part if it could cause engine damage worse fire in that area due to a design flaw.

The contact owns a 2021 Hyundai Elantra. The contact stated while driving 30 MPH, the vehicle decelerated and lost motive power. The contact stated that the vehicle went into LIMP Mode. The vehicle was taken to the dealer on three occasions; however, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 61,000.

Horn stopped working.

car problems started with back up camera not working, it has caused dash lights to go out, headlights to go out while driving safety sensors to sound for no reason. I have also started having problems with radio flashing and going blank. The vehicle has been checked by Hyundai dealer they did say back up camera bad but no answers for rest of issues.there were no warning lights prior to any of these problems. I still do not know what is really wrong and cannot drive vehicle at night or bad weather for fear of losing headlights. Vehicle is 2021 hyundai elantra with 10,500 miles on it.

Twice now when starting the car all the driver safety systems will show a warning that they are not working and the message is that the car is not save to drive. A bunch of warning signs will go off and the wheel locks. The brake system has also locked up. I captured it on video, but it won’t let me upload it here.

While driving on the freeway around 70 mph the car seems to reboot, it slows down and coast and the dash computers shutdown and restarts.

A squirrel chewed my wiring into the temperature coolant sensor. I had to have two different rental cars for six weeks before I received my car back. Nothing happened to those vehicles during those six weeks. Within a week of having my car (2021 Elantra) back, a squirrel chewed more wiring. My car is now needing another repair. This is a known issue with Hyundai as well as other makers. I feel it’s pretty compelling evidence that there is a problem as two vehicles were not bothered by squirrels for six weeks and then my car comes back and it gets chewed up again right away. All cars were parked on my driveway.

On August 17, my new Elantra lost power steering, and most safety related features. Most all instrument warning lights came on. Was able to get car to dealer service where they kept car overnight, and reset the error lights. They told me, they recorded the computer codes, but could not find the cause of the problem. On August 26, again the instrument warning lights suddenly came on AGAIN. Took car to dealer service, where they kept car almost 2 weeks, but could not find the cause. They recorded computer codes. I contacted Hyundai, and a case number was established, but no fix has been found. Case worker has been difficult to reach. My wife refuses to drive this car. New electrical problems: 1.Driver's door handle light not working at night when approaching door. 2. Receiving false emails that car doors are not locked, but they are locked. 3. Using myhundai, shows door are not locked, but they are. When using application to lock doors, false message back that a door is open. 4. Navigation cuts off intermittently. 6. Gasoline consumption computer resets sometimes, other times it does not. 7. Remote start application does not work, says my door is open. 8. Items missing from center display menus. (Door light, reset gas mileage etc) Car has to go back to dealer service for needed repairs.