2021 Hyundai Santa FE Problems

What owners report

Owners of the 2021 Santa Fe most often describe transmission trouble — harsh or delayed shifting and, in some cases, sudden loss of drive — plus sudden engine stalls or loss of power while driving, often with little or no warning. A separate group of complaints covers inoperative horns, blank or glitchy rearview camera images, and glass (sunroof or windshield) that cracks or shatters without impact. Many of these reports come in at low mileage, and several owners mention the same complaints recurring after dealer repairs or recall work.

1. 1
   Engine

   Engine stalls or loses power while driving

   • 43 complaints (26%)
   • median 21,000 mi at 2.8 yrs old (9 state mileage, few)
   • filed 2021–2026

   Owners describe the engine shutting off while driving at highway or city speeds, sometimes with a beep or warning message and sometimes with no warning light at all, and in some cases the vehicle will not restart until it is shifted into park. Dealers have variously performed engine replacement, replaced fuel injectors, applied an ECM update for the idle stop-and-go system, or told owners no fault could be found. Some complaints note back-ordered parts and repeat visits. Reported across a wide mileage range, from under 15,000 miles to about 67,000 miles, with several reports at highway speeds.

   5 related service bulletins

   What to check: Ask for service records covering idle stop-and-go or ECM updates and any injector or starter work, and note whether the engine idles roughly or hesitates on a cold start. Check for a stored check-engine code with a scan tool before buying.

   2 excerpts from owner complaints in NHTSA records

   “There were 2 instances where my vehicle stopped. Once I was driving 15mph and it said “Put car in Park”. The 2nd, I was driving 45mph and the vehicle said “Step on the Brake to start car”. I have also had 2 instances where my odometer just keeps going up and down. He 2nd instance, the car was making a ticking noise and hazard along with other lights were flashing.”

   NHTSA complaint #11518995, filed 2023-04

   “I have been having problems with the vehicle. Apparently it has problems with the start-stop system ; the car turns off even while driving , sometimes it turns on and off by itself while driving . Took it to the dealer and unfortunately this continues to happen. It worries me because while driving on the expressway it turned off and then on by itself leaving me without control of the vehicle for a few seconds . …”

   NHTSA complaint #11540213, filed 2023-08
2. 2
   Transmission and drivetrain

   Transmission slipping, harsh shifting or loss of drive

   • 39 complaints (23%)
   • median 15,600 mi at 2.5 yrs old (11 state mileage)
   • filed 2021–2026

   Complaints describe hard or delayed downshifts, the transmission slipping out of gear while driving, and in some cases the vehicle dropping into neutral or losing motive power, sometimes after the engine revs without the car moving. Several owners say dealers replaced the transmission (one reports two replacements), while others report the failure could not be duplicated or persisted after a recall software update. Some complaints tie the symptom to the 22V746000 transmission pump recall. Reported from very low mileage up to about 100,000 miles, with many cases logged between roughly 15,000 and 60,000 miles.

   Recall 22V7460004 related service bulletins

   What to check: During a test drive, watch for clunky or delayed downshifts and any hesitation when merging or accelerating. Ask whether the 22V746000 recall and any transmission control software update were completed, and whether the transmission fluid has been serviced.

   2 excerpts from owner complaints in NHTSA records

   “10/22/21, Mileage ~720, while driving on the highway I had two incidents when the car did not respond to throttle application. In the first instance while attempting to accelerate mildly on a level road the rpm went to 3500 with no acceleration. I backed off the throttle and the car resumed normal operation. In the second instance while attempting to accelerate mildly on a level road the rpm showed about 1500 with no acceleration. I backed off the throttle and the car resumed normal operation. …”

   NHTSA complaint #11437869, filed 2021-10

   “Transmission goes out of gear while driving. It was taken to Hyundai for inspection 5 times. Goes out of gear when driving. Making a turn at a light, the car stopped in the intersection, I could have been hit by another car. Car was taken in for a transmission recall on 02/07/2023, ever since they reset the transmission, the car goes out of gear again. It didn’t happen before recall and computer reset. The car has been back to the Hyundai dealer on at least 5 times and has been there for a full week now. They still have the car. …”

   NHTSA complaint #11548276, filed 2023-10
3. 3
   Visibility (wipers, defrost, mirrors)

   Sunroof or windshield glass cracks without impact

   • 14 complaints (8%)
   • median 10,000 mi at 1.4 yrs old (5 state mileage, few)
   • filed 2021–2026

   Owners report the panoramic sunroof glass or the panel above the windshield shattering or cracking with a loud noise while parked or driving, with no object seen striking it. In some cases dealers directed owners to their insurance or declined warranty coverage. Other complaints describe windshield cracks spreading from a small impact. Reported from a few hundred miles up to about 46,000 miles, sometimes within weeks of purchase.

   Recall 21V00M000

   What to check: Inspect the sunroof glass and windshield edges for chips, hairlines or prior replacement, and ask whether any glass repair was done under warranty or insurance.

   2 excerpts from owner complaints in NHTSA records

   “I was driving on the freeway with the sunroof closed when I heard a very loud bang. I pulled off to check the exterior but saw nothing. I drive for about an hour more when it started sounding like the sunroof was open. I pulled over to check it, and it was destroyed..shattered with a large hole in it. Called Hyundai who said report to insurance even though the car is less than 1 month old.”

   NHTSA complaint #11415657, filed 2021-05, 500 miles

   “While backing out of our garage, the “eyebrow” glass portion of the panoramic sunroof shattered. Nothing struck the glass. Our insurance is paying for the repair and rental car for a week. Hyundai will not cover the glass damage under the warranty. Online searches indicate that Hyundai has a lengthy history of faulty panoramic sunroofs.”

   NHTSA complaint #11492466, filed 2022-11
4. 4
   Electrical system

   Horn stops working

   • 17 complaints (10%)
   • median 55,000 mi at 4.2 yrs old (1 states mileage, few)
   • filed 2023–2026

   Owners report the horn simply stops working with no warning, and several say the dealer replaced it more than once, in some cases with the replacement failing again within months. Complaints link the failure to water or foreign material reaching the horn unit. Hyundai has issued warranty extensions covering horn replacement for this condition on certain Santa Fe model years. Reported from low mileage up to around 55,000 miles, with some owners describing repeat failures shortly after each repair.

   6 related service bulletins

   What to check: Test the horn before purchase and ask whether it has already been replaced. Ask the dealer whether this vehicle is covered by the horn warranty extension and confirm the coverage terms in writing.

   2 excerpts from owner complaints in NHTSA records

   “Vehicle horn continues to stop working. Problem occurred within a month of purchase. I have had it repaired 3 times, and each time it has been repaired it works for only a few days and then stops working. I am tired of paying to have it fixed, only to work a few days. It has been a safety concern as I have not been able to alert pedestrians, other vehicles, or animals to my presence. Having a working horn is a required safety feature for my employment and driving on company property.”

   NHTSA complaint #11588898, filed 2024-05

   “I have a problem with the horns on this vehicle. The horns have been replaced by the dealer 5 times so far and they are out again. THE HORNS LAST ABOUT 1 TO 2 MOUNTHS. There is no warning that the horn stopped working, and if it's needed in an emergency to avoid an accident and doesn't work, myself and others could get hurt. This is ongoing problem that should to be addressed.”

   NHTSA complaint #11614616, filed 2024-09
5. 5
   Back-over prevention (rear camera)

   Rearview camera blank, green or distorted

   • 6 complaints (4%)
   • median 21,000 mi at 3.4 yrs old (3 state mileage, few)
   • filed 2022–2026

   Complaints describe the backup camera showing a black screen, a green or glitchy image, or not coming on at all when reverse is selected, sometimes intermittently and sometimes showing an image while driving forward. Some owners say the dealer could not duplicate the problem or had no record of the recall repair; one reports the camera failing again after recall work was done. Mostly reported between roughly 16,000 and 50,000 miles, often described as intermittent.

   Recall 24V879000

   What to check: With the vehicle in reverse, check the screen for blank, green or distorted images, and ask whether the 24V879000 camera recall was completed with documentation.

   2 excerpts from owner complaints in NHTSA records

   “My rear back up camera intermitting stops working. I can shift into reverse sometimes and the camera does not come on at all, other times the screen blinks and other times the screen has green lines and glitchy lines. The camera will also come on while I'm DRIVING forward”

   NHTSA complaint #11756508, filed 2026-08

   “The contact owns a 2021 Hyundai Santa Fe. The contact stated that the vehicle was repaired under NHTSA Campaign Number: 24V879000 (BACK OVER PREVENTION), but the failure occurred. The contact stated that the back over prevention camera displayed a distorted image or a black screen occasionally while the vehicle was in reverse(R). The failure obstructed the driver's visibility, which prevented the driver from safely operating the vehicle. …”

   NHTSA complaint #11724716, filed 2026-03, 50,667 miles

Buying note. A pre-purchase inspection that includes a scan tool check, a highway test drive to feel the transmission, and a look at recall completion records will tell you more than the mileage alone on this model year. Ask for service history showing transmission, engine and horn work, since several complaints describe symptoms returning after repair.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.