2021 Hyundai Sonata Transmission Problems

Your 2021 Hyundai Sonata has an active safety recall for potential fuel tank pressurization and fire risk. You brought it to a dealership because of a check engine light, reduced engine performance, and a diagnostic code (P14EE) that matches the recall issue. The dealership refused to handle it as a recall repair, instead charging you a diagnostic fee and trying to sell you a fuel pump repair, and they replaced a fuel system sensor without your permission. The dealership did not document whether they actually checked the recall condition or provide test results showing the recall was ruled out. The fix will likely involve a complete fuel system inspection and potential fuel tank or fuel system component replacement as part of the safety recall.

Your engine is triggering a P0471 diagnostic code (related to exhaust pressure sensing) before reaching 55,000 miles, and the problem persists even after you've had it repaired once. This suggests the underlying issue may not have been fully resolved. You'll likely need to have the vehicle scanned again and the exhaust pressure sensor system inspected more thoroughly.

Your car suddenly lost heat in cold weather without any warning lights or gauge indicators appearing. You discovered the coolant level was critically low, but after adding coolant, the level dropped again immediately with no visible leaks underneath. The owner suspects an issue with the EHRS (engine heater recirculation system) is causing the coolant to disappear, which could have caused engine damage if this occurred in hot weather.

The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at 30 MPH and depressing the accelerator pedal, the vehicle failed to respond and lost power. The vehicle was coasted over to the right side of the road, turned off, restarted, and returned to normal functionality. An independent mechanic was contacted. The vehicle was taken to an independent mechanic to be diagnosed; however, the diagnosis was unknown. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 22V746000 (POWER TRAIN); however, the VIN was not included in the recall. The manufacturer was not notified of the failure. The failure mileage was 35,000.

2021 Hyundai Sonata with approximately 39,000 miles. On [XXX], the dashboard displayed the following message "Shifter system malfunction! Service immediately" When the warning appeared, the vehicle shifter button would not function, creating a traffic safety risk. History: Dealer service history shows the transmission was replaced on the vehicle under warranty on 08/30/2021 with 2,212 miles with no campaign/recall issued. Dealer states there is no recall campaign on this vehicles specific VIN # and NHTSA currently shows no open recalls for this vehicle. However, Hyundai advertises an 8-Speed DCT Safety Recall for the same year, make and model, and describes this identical issue, but has left this vehicle's VIN# out of scope for this recall, which is continuing to demonstrate the same issues. Current dealer/manufacturer response: On 9/4/2025, the dealer declined warranty or recall repair unless the fault was active on their diagnostic scan at the moment the scan was performed. A photo was provided to the mechanics of the dashboard showing the transmission service warning, with current mileage. The dealer advised there were no diagnostic log history showing the transmission error code even with photographic proof and attempted to return the vehicle to me. I have rejected the return of the vehicle and advised that this needs to be escalated, because if logs are not appearing, this is even a bigger cause for concern and that the vehicle is a safety hazard. Concern: Because this vehicle required an early transmission replacement and is now exhibiting new transmission/shifter warnings, I am concerned the failure relates to the known transmission/shifter recall on this model and that the recall scope and/or remedy is incomplete for the affected vehicles including my vin #. It is also possible the dealership is attempting to run out the warranty which expires in 3 months. Vehicle, photo of the warning, and service records are available for inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

After initial startup and drive for a short time, I come to a stop. Then after vehicle doesn’t want to accelerate as it normally would. Vehicle struggles to gain speed but, the engine revs excessively. I pull off the road and come to a stop and try to accelerate again and the same thing happens. I shut the vehicle off and wait a few minutes,then restart and the vehicle accelerates normally again. There were no check engine lights the when this has happened.

My transmission on my 21 Hyundai sonata n line has failed. It began when the car needed to emergency brake when someone jump into my lane on the road. There’s grinding, and whining in the transmission along with delayed shifts, jerking and a burning smell that comes through the vents of my car upon start up. The recall on this transmission is because it may become defective. I bought the vehicle from a Honda not a Hyundai dealer in March of 2023 the recall campaign closed out Jan of 2023. According to Hyundai records show that the TCU update remedy was performed Jan of 23. However, even though that TCU update was performed, 2 years later my transmission began to fail. I brought it to my local dealer for a transmission drain and refill not a flush. Per the service manual it’s a drain and refill however they flushed it which caused the transmission to worsen. I took it back to have it diagnosed and I was told I needed my transmission replaced. Didn’t even explain why or go into further detail what was wrong with the transmission. I brought up the recall on the transmission and they did nothing to honor it. Now I’m stuck with a car with a broken transmission i can’t afford to fix and I’m gonna be forced to hand the car over to the bank. If this recall can still be honored please help.

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.

Issue with DCT transmission. Unknown remedy

I have been to the dealership on three separate occasions due to the engine misfiring. Two ignition coils have been replaced so far and I recently returned to the dealership for the same issue. This time however, not only did the engine light come on but I went from a full tank to less than a quarter of a tank and the engine is making backfiring sounds. At that time the dealership said that they could not recreate the issue, I got my oil changed and went home. That was a week ago, I am back at the dealership today for the same thing; fuel dumping and backfiring sounds. While at the dealership today it turns out those backfiring noises were the fuel tank expanding so much so that it kept popping the seat up. They deemed the car unsafe to drive and it is currently at the dealership.

Vehicle began to lose power while on highway. The loss of power occurred for a few seconds, then came back. Shortly after, the RPM began changing uncontrollably. Tried shifting to manual control using paddle shifters and was able to maintain steady RPM until vehicle software switched back to automatic and RPM swung crazy again. Endangered other vehicles on road due to loss of power and fluctuations of transmission. Once parked, vehicle did not change to neutral, drive, reverse. Both manufacturer and insurance are/have reviewed vehicle and are working on a fix. No warning lights. Only indication was minor loss of power prior to incident. Loss of power was not considerable nor for a prolonged period of time.

I took off from the house about 1 mile the car stop in the middle of the road with no warning, lights or anything. Thank God I didn’t get an accident we took the car to the dealer and the dealer telling us it’s not covered by warranty. This is 2021 Hyundai sonata lease with only 44,000 miles my wife is so scared to driving Hyundai anymore. We talk to the dealer they don’t give us loaner car still one week from now they are telling us to pay $13,000 for the repair.

The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the vehicle lost motive power with the oil warning light illuminated. The contact was able to restart the vehicle; however, the failure recurred. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The contact related the failure to NHTSA Campaign Number: 22V746000 (Power Train); however, the VIN was not included in the recall. The failure mileage was approximately 41,000.

The contact owns a 2021 Hyundai Sonata. The contact received notification of the NHTSA Campaign Number: 22V746000 (Power Train) however, the contact stated that on numerous occasions while driving at various speeds, the accelerator pedal was depressed however, the vehicle decelerated and went into "fail-safe" mode. The vehicle was taken to the dealer where it was diagnosed that the transmission control unit software needed be updated. The vehicle was repaired; however, the failure recurred. Additionally, the contact stated that prior to the recall repair, while driving at an undisclosed speed, the vehicle failed to accelerate as needed. The vehicle was taken to the dealer and the transmission was replaced. The vehicle was not repaired. The manufacturer was notified of the failure and the contact was provided a case number and an appointment was scheduled to take the vehicle back to the dealer. The failure mileage was approximately 12,100.

Took vehicle in for transmission recall on June 12th. After picking up vehicle the vehicle it was shifting harshly. On the 17th my vehicle had a code come up that said to park it and contact the dealership ASAP. Transmission code P1C2D03. The recall was supposed to prevent this, not cause it.

Car transmission seemed to make a "clunking" sound when selecting gear from park. The car would not accelerate, the throttle seemed to be stuck and the transmission would try to downshift, but the car was not picking up speed. I eventually pulled off the road into a parking lot and turned the car off. I then restarted the car and it seemed to clear the problem, but no warning lights ever came on, and no error codes were displayed on the instrument cluster.

The contact owns a 2021 Hyundai Sonata. The contact stated while driving 65 MPH and attempting to accelerate, the vehicle failed to respond with the check engine warning light illuminated. The contact also heard a knocking sound coming from the vehicle. The contact pulled over on the side of the road and turn off and restarted the vehicle and the vehicle started operating as designed. The vehicle was taken to the dealer and the contact was informed that the transmission and engine needed to be replaced. The manufacturer was contacted but offered no assistance. A case was filed. The failure mileage was 2,700.

The contact owns a 2021 Hyundai Sonata. The contact became aware that the VIN was included in NHTSA Campaign Number: 22V746000 (Power Train); however, parts to do the recall repair were not yet available. The local dealer was contacted. The contact stated that the vehicle would delay while starting. The vehicle was taken to the dealer where it was diagnosed but no issues were found. The vehicle was not repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue and informed the contact that a recall notification would be mailed to him in December. The failure mileage was approximately 15,000. VIN tool confirms parts not available.

The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle made abnormally loud sounds. The vehicle was taken to the dealer where it was diagnosed that the transmission needed to be replaced. The dealer informed the contact that they were awaiting approval from the manufacturer to perform the repair. The vehicle was not repaired and remained at the dealer. The manufacturer was made aware of the failure. Upon investigation, the contact related the failure to Manufacturer Recall Number: 236 (Power Train) included with the VIN; however, he had not yet received notification. The failure mileage was approximately 28,000.

My transmission went bad on my new car. Didn’t have my car for 4 month August 12 2021