Hyundai Sonata Complaints (2021)
190 consumer complaints on file.
- #11642341February 12, 2025ENGINE, ELECTRICAL SYSTEM
On 5 separate occasions the car has shut itself off while driving. After the first 2 times the car was taken to the dealership where they found nothing wrong and told us to replace the battery. The battery was replaced by the dealer and within the next two weeks the car shut itself off while driving 3 more times. The car will always start back up again right away. This is a very dangerous situation.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11641851February 10, 2025STRUCTURE:BODY
Sunroof exploded on the highway with no one in-front of me to kick up any rocks or debris.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11641099February 6, 2025UNKNOWN OR OTHER
I live northern suburbs of Illinois. I was backing out of a parking spot when I couldn’t switch gears from Reverse to Drive. My car showed flashing lights and said system malfunction and service immediately. I had to put the safety brake and turn of my car. It took a couple minutes to reset and turn on my car for me to move it.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11639354January 29, 2025SERVICE BRAKES, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
Was driving in reverse out of garage and ABS brakes were applied like I hit a patch of ice stopping the car. Released when applied pressure to brake. Then while on highway going 60 miles an hour the emergency brake system went on for no reason applying pressure and red light came on the dash with a left facing arrow. System released within a few seconds but scared me and I still have to drive this car on highway.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11636925January 19, 2025UNKNOWN OR OTHER, ENGINE
My 2021 Hyundai Sonata Hybrid seems to be leaking coolant into the exhaust system. Various reports online indicate that this is a consistent issue with 2020-2022 Hyundai Sonata Hybrid models. A lot of the reports indicate that owners have tried getting theirs cars repaired for the same issue I have a various dealerships all across the US, but either haven't had any luck or have had a temporary fix for the issue, which proceeded to occur again every couple of months. I personally have had my car inspected by my personal dealership and they have confirmed the issue and have mentioned that other owners have brought theirs in to be checked out, but haven't really had luck. I believe that Hyundai should take responsibility for this and issue a recall on the affected models. I bought the car in good faith hoping for reliability but haven't had it for even 6 months now and this problem is here. For safety or myself and others on the road, this models of the Sonatas need to be recalled and repaired IMMEDIATELY. For reference, here is a reference for the complaints people have made online regarding the vehicle: 1. [XXX] 2. [XXX] . (THE RESPONSES HERE ARE VERY DETAILED) [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11635700January 13, 2025ENGINE
EHRS Coolant Leak- problem started in [XXX] when engine overheated. The weather in Michigan in inclement and being stranded in the intense cold can lead to loss of life. I had it towed to a Hyundai dealership that was unable to find the problem and in attempting to "find a leak" used the incorrect dye, necessitation transferal to another more competent dealership where the problem was diagnosed and was fixed with a replacement part. In December 2023 a TSB 23-EM-009h was issued by Hyundai describing this problem and issuing a part (Center Muffler). I was not informed and the problem recurred. currently this is the third episode and Hyundai after paying 95% of the previous cost, now only agrees to pay 85% and denies reimbursing me for the car rental. Warning lights appeared with all 3 occurrences. Hyundai should have issued a recall to obviate this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11634145January 5, 2025POWER TRAIN
2 years after purchasing a new vehicle, the transmission began to pop and cause the car to jerk upon a cold start, RPM would increase but the speedometer would not go over 20mph. There were no error messages or alerts. I reported it several times, and the dealership technicians could not duplicate the issue and stated that the car was driving as it was designed even after providing video proof. They were later able to partially replicate the issue when the car popped and jerked after a cold start and then replaced the transmission, however, it did not resolve the issue. 1 month after the repair the car started having the same issues. After several trips to the service department, they have still been unable to duplicate the issue even with recent video proof. Based on how the technicians enter notes, the manufacturer refuses to pursue any alternative method for figuring out what is going on. This is risky because my car, upon starting cannot be safely driven and the car will shutter upon stopping at lights sometimes.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11632087December 23, 2024ELECTRICAL SYSTEM
In June 2024, I was driving my vehicle when I started to smell burning from under the dashboard. As I continued to drive, the smell got worse, and on my way to the dealer, my air conditioner stopped working. I took my car back to the dealer for service, and several days later, I was told that my car needed a hardness connected to several components in the engine compartment. I remember while I was dropping off my car at the dealer, one of the service advisors told me that it was good. I drove to the dealer because the car could have gone on fire. It's now six months later, and they have not fixed my car. I was told they're awaiting parts from Korea to complete the fix. My concern is that this part can cause a fire. Why did Hyundai not recall these vehicles? Hyundai knows about the problem. I was told that I'm not the only one waiting; supposedly, there are 100's more customers waiting for this part.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11630638December 13, 2024ELECTRICAL SYSTEM
the car randomly goes into dead or limp mode and unable to start. need to jump start it to come alive. No codes shown once its jumstarted. it has happened at random on several occasions.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11630327December 12, 2024ELECTRICAL SYSTEM
When the vehicle is turned off the 12v Lithium battery will die. This is a intermittent occurrence that has happened approximately 7 times since [XXX]. Today is December 12, 2024. The car is currently at All Start Hyundai dealership in Pittsburg, CA. This dealership initially denied the car had a problem because they could not duplicate it in a 24 hour period and told me "the car is operating as designed". When I insisted they check the health of the battery, the service department would not do this until they received technical advise from Hyundai headquarters (HQ). It is a multistep process to get to the battery and requires removing the back seat. When HQ advised the battery check, the service department found the battery was swollen and needs to be replaced. I have found information on chat boards and YouTube where other car owners having the same issue. Why hasn't Hyundai HQ issued a recall and replaced all the batteries? The dealership has told me there are batteries in inventory in a warehouse in Los Angeles California, yet HQ has them on hold on back order status. What and why would the battery not be available for the cars having the issue? I believe a swollen 12v Lithium battery is a safety hazard and should be recalled. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11628830December 4, 2024ELECTRICAL SYSTEM, ENGINE
This car has two problems. 2 weeks I was driving on the highway. All the sudden the shutoff and lost all power on the car. Thank god I pulled to the side of the road safely. Turned the car off and turned it back on. The car started to run normal. I took it to mechanic. They scanned the car with their computer. Said the car has no problems. Tested the battery and all other components. No problems found. This happened again yesterday on the highway driving. Car engine shuts off again. The car has engine problems as well. But Hyundai denies to address it.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11627928November 29, 2024UNKNOWN OR OTHER, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
On three separate occasions, while going very fast (60-78 mph), the automatic emergency braking system turns on. The warning lights flash and there is some type of warning noise. I don't even know if it starts to break because it scares me so much, I just press the gas. It turns off within a couple of seconds, but that is not the point. If I didn't react so fast, I am unsure of what could actually happen.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11619346October 11, 2024ELECTRICAL SYSTEM
The BMS module within my cars hybrid system failed causing a parasitic drain on the hybrid battery. The dealership where the work was performed would have to be contacted for pictures. The hybrid battery system swole to a dangerously inflated level and did not produce any codes for an OBD reader to pickup. This has caused the dealership to turn my car away multiple times before finally performing the in depth inspecting required to verify battery swelling. This is a known problem throughout the internet I searched "2021 hyundai sonata hybrid battery dying every day" reddit has plenty of user with the same issues. I am not aware of who has inspected my battery besides the dealership. There was no warnings at all the only reason my battery was finally looked at is because of my persistence.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11618313October 6, 2024ENGINE, ELECTRICAL SYSTEM
2021 Hyundai Sonata 59,850 miles RPM jumps to around 1,300 at zero miles on occasion. If I am stopped, at a red light or behind other stopped autos, the vehicle jumps forward when I take my foot off the brake. Because this happens quite often, I am aware of this and keep my foot on the brake until other vehicles are out of the way to avoid bumping into them. When this happens, I can cruise at 30 miles per hour without having my foot on the accelerator, I can slow down or stop by applying the brakes but the engine RPM stays at 1,300. If I stop and shut off the vehicle and restart, the operation goes back to normal but occurs again later. The Hyundai dealer has had the vehicle back 9 times but the issue continues. The first few times, they could not find an issue, I returned to the shop when this was happening and the service manager and a technician observed this condition, the EGR valve was replaced. Was OK for a bit but condition returned, the computer was then replaced. Condition continued. Brought the vehicle back and a scan was done and system “re-learned. After a short time the condition returned. Went back to the service center and they did another scan and another re-learn. Condition returned 4-5 days later. Problem still not resolved. Have 59,850 miles on the vehicle, warranty expires at 60,00 miles. This started around July 1, Now October 5. Waiting for a loaner so the service center can drive it around until the situation occurs and they can bring it in immediately for diagnosis. This is the same issue as reported for the same year vehicle in July 2022.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11616027September 23, 2024ELECTRICAL SYSTEM
The contact owns a 2021 Hyundai Sonata Hybrid. The contact stated that the key fob was inoperable and after using the key to manually open the door. The contact stated that the vehicle failed to start while pressing the START/STOP button. The vehicle was towed to the local dealer, but the cause of the failure was not determined. The contact was advised that when the failure occurred, to start the vehicle, the battery reset button should be pressed before pressing the START/STOP button. The manufacturer was not contacted regarding the failure. The failure mileage was 24,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11615509September 19, 2024ENGINE
I purchased this vehicle brand new. It is still under factory warranty. It has approximately 14k miles on it. I have followed all recommended maintenance procedures. During a routine maintenance appointment at the dealership (Vancouver Hyundai 6802 NE 40th Street, Vancouver WA 98661) they identified a catastrophic engine failure due to internal component deterioration and the engine needs to be replaced. They have had my vehicle in their possession since [XXX] of this year for a total of 134 days. I have a case number at Hyundai # [XXX]. They have not been helpful in providing any information and as of now, I do not know when they even expect to receive a new engine. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- Crash:
- Yes
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11615411September 19, 2024FORWARD COLLISION AVOIDANCE, ENGINE
The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the vehicle lost motive power. Additionally, the Forward Collision Avoidance failed to function as intended. The contact stated that the sensor was braking prematurely. The vehicle was taken to the dealer; however, the failure was not duplicated. The contact stated while driving out of the driveway, the vehicle lost motive power. The vehicle failed to restart. The dealer was contacted and made aware of the failure. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was unknown.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11613234September 7, 2024ELECTRICAL SYSTEM
Blower motor on 2021 Hyundai Sonata SEL stopped working. Same issue happened on my 2020 Hyundai SEL and currently waiting on my 2020 Sonata to be fixed. Hyundai technician said the wiring harness had a crack and it’s why my 2020 Sonata’s Blower motor stopped working. It’s now three months since they diagnosed and ordered the wiring harness but supposedly it’s still on back order and I’m left with a hot car this entire summer and possibly a cold car come this winter. Now it looks like I will have the same issue with my 2021 Hyundai Sonta.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11612820September 5, 2024ELECTRICAL SYSTEM
Fuse box has a defect causing the AC blower motor to intermittently not work. Appears to be the result of loose connections between the fuse box and the fuse itself. The receptacle for the fuse is clearly burnt/melting, and appears to pose as a fire hazard as a result. The car is currently in the shop for repair on this part, but won't likely be fixed for a month+. I do have photos of the damaged parts, should it be requested. The car was taken into a Hyundai dealership for repair work in November 2023, and I was told the fuse had blown but that they fixed it. I was never told about the box appearing damaged/melting at that time, or this being a common problem. It worked again till July 2024. Car was just dropped off 9/3, due to backlog of cars at dealership. The only symptom of issue was the AC blower motor would stop working at random. It would turn back on/off while driving. This seems to be due to the loose connections between fuse box and fuse.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11612394September 3, 2024ENGINE, ELECTRICAL SYSTEM
On three separate occasions over the last two months, while driving, an alert comes on that says check hybrid system then the vehicle powers off. When this happens, you lose the ability to accelerate break steer, and I have been lucky each of those three times and that I was in a situation where there was not much traffic. I am not able to drive the vehicle at this time. I have reported the problem to Hyundai and they want me to drive the vehicle to the dealership for another check of it. They have looked at it once before and have not been able to diagnose a problem. It is unsafe to drive and they are not willing to assist in getting the vehicle to the dealership without me getting it over there.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0