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Total NHTSA Complaints
182
Owner filings recorded
#1 Reported Problem
Engine & Cooling
48 reports (26.4%)
Crash Incident Reports
8
Filings citing a crash
Fire & Injury Reports
3
0 fire • 3 injury filings
Defect Investigation Analysis

Executive Problem Findings

AutoUtility currently tracks 182 official NHTSA owner defect complaints for the 2021 Hyundai Sonata. Engine & Cooling issues are the most frequently reported category, appearing in 48 complaints (26.4% of submitted records). Among these NHTSA complaint records, 8 filings cite a crash, 3 report one or more injuries.

Methodology Notice: Consumer complaints are unverified voluntary submissions to the NHTSA Office of Defects Investigation (ODI). Filings are not normalized for sales volume or vehicle mileage and do not constitute an audited component failure rate.
Incident & Severity Profile
  • • Total Owner Reports: 182 complaints submitted under federal penalty.
  • • Primary Subsystem: Engine & Cooling accounts for 26.4% of submissions (48 reports).
  • • Secondary Systems: Electrical System (42), Fuel & Propulsion System (35).
  • • Crash Incidents: 8 filings cite an impact or collision.
  • • Thermal Incidents: 0 filings cite smoke or fire.
  • • Reported Casualties: 3 injury filings • 0 fatality filings.
Category Distribution

Reported Defect Categories for 2021 Hyundai Sonata

Factual proportion of owner complaints categorized by automotive subsystem in NHTSA records

Engine & Cooling
48
26.4%
Electrical System
42
23.1%
Fuel & Propulsion System
35
19.2%
Powertrain & Transmission
25
13.7%
Driver Assistance & Safety Tech
14
7.7%
#1 26.4% SHARE

Engine & Cooling

48 owner complaints submitted to NHTSA ODI for this subsystem.

⚠️ 1 Crash
#2 23.1% SHARE

Electrical System

42 owner complaints submitted to NHTSA ODI for this subsystem.

✓ 0 Incidents
#3 19.2% SHARE

Fuel & Propulsion System

35 owner complaints submitted to NHTSA ODI for this subsystem.

⚠️ 1 Crash 🩹 5 Injury
⚠️ 2 Associated Recall Campaigns
#4 13.7% SHARE

Powertrain & Transmission

25 owner complaints submitted to NHTSA ODI for this subsystem.

✓ 0 Incidents
⚠️ 1 Associated Recall Campaign
Deterministic Text Analysis

Recurring Symptoms Identified in Owner Reports

Specific mechanical, electrical, and driver-assist defect symptoms identified via deterministic narrative analysis

Powertrain & Transmission 7.1%

Loss of Motive Power While Driving

13 complaint narratives describe this symptom.

NHTSA Narrative Match
Engine & Cooling 4.4%

Engine Overheating / Temperature Warning

8 complaint narratives describe this symptom.

NHTSA Narrative Match
Engine & Cooling 3.3%

Engine Coolant Intrusion / Oil Leak

6 complaint narratives describe this symptom.

NHTSA Narrative Match
Federal Oversight

Official NHTSA Defect Investigations (2)

Formal engineering analyses and preliminary evaluations opened by the NHTSA Office of Defects Investigation

ODI Action #DP22005 CLOSED Defect Petition (DP)
Opened: 2023-01-27 • Closed: 2023-08-07
Subject / Subsystem
Pedestrian alert sounds
Affected Component
ELECTRICAL SYSTEM:PROPULSION SYSTEM
Recall Linkage
NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles. The standard applies to hybrid and electric vehicles that have a gross vehicle weight rating of 4,536 KG or less or are defined as low-speed vehicles. The standard became fully applicable to all such vehicles manufactured on or after March 1, 2021.On January 27, 2023, NHTSA opened Defect Petition (DP) 22-005 to evaluate the subject matter described in the petition. On June 24, 2023 and as supplemented on June 25, 2023, the petitioner notified NHTSA he was withdrawing his petition. The petitioner indicated that, based on his review of data, there is no justification for asserting potential benefits that could be derived from actions sought by my petition. Based on the petitioner's withdrawal, DP22-005 is closed. Closure of this DP does not represent a determination by NHTSA regarding the subject matter of the petition.
ODI Action #DP22003 CLOSED Defect Petition (DP)
Opened: 2022-09-12 • Closed: 2023-12-12
Subject / Subsystem
Loss of Motive Power
Affected Component
ENGINE
Recall Linkage
No direct recall linkage
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints indicating that the subject vehicles were experiencing rapid loss of engine oil due to oil drain plug back outs, resulting in loss of motive power and/or catastrophic engine damage. Additional complaints were provided which alleged that the oil drain pans lack sufficient structural integrity and are susceptible to cracking. The petition itself can be reviewed at NHTSA.gov under ODI number 11481745. On September 12, 2022, the Office of Defects Investigation (ODI) opened Defect Petition (DP22-003) to evaluate the Petitioners’ request. The Petitioners have provided additional complaints within four supplemental letters dated January 31, 2023, March 21, 2023, May 23, 2023, and August 4, 2023. ODI’s evaluation included the review and analysis of the complaints and supporting information submitted by the Petitioners, as well as additional complaints submitted directly to NHTSA which referenced either the oil drain plug or a crack in the oil pan. After reviewing the available data, ODI has not identified evidence that would support opening a defect investigation into the oil drain pan assemblies of the subject vehicles. Based on a review of the available information, a loss of motive power resulting from an oil drain plug back out has not occurred between the initial sale of a vehicle and the completion of its first oil change. If during an oil change service, a technician fails to remove the existing drain plug gasket before installing a new gasket, it is likely that a proper seal between the drain plug and the oil pan will not be made. An improper seal between the drain plug and oil pan could lead to the backing out on the drain plug, resulting in the sudden loss of oil while driving. Additionally, the provided examples of oil pan cracks were localized to the immediate vicinity of the oil drain plug and/or appeared to be the result of direct-contact with a tool during servicing.  There is no information to support that a vehicle-based defect exists relating to the oil pan assembly, and instead the documented incidents are related to the failure to follow the proper maintenance procedures during oil change service. In October 2023, Hyundai published a Technical Service Bulletin (TSB) that provided detailed instructions for oil change service on its gasoline powered vehicles, specifically highlighting the need to remove and replace the existing drain plug gasket prior to reinstalling the drain plug. After a thorough review of the material submitted by the petitioner, the information already in NHTSA's possession, and the potential risks to motor vehicle safety implicated by the petitioners' allegations, NHTSA does not believe that a formal investigation is warranted. Therefore, the petition is denied. A Federal Register Notice (FRN) further detailing NHTSA’s reasons for denial of the petition will be published. The reference numbers for the complaints to NHTSA cited by the petitioner can be found in the petition submission documents in the public file for DP22-003. To review those complaints and the additional complaints ODI added to its evaluation which are cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.
Consumer Filings

Recent NHTSA Owner Reports for 2021 Hyundai Sonata

Representative defect filings submitted by owners to the NHTSA Office of Defects Investigation

Fuel & Propulsion System ODI #11758588
Filed: 08/21/2026
Defect Report

"The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline); however, the part to do the recall repair was not yet available. The contact stated that while driving at an undisclosed speed, the vehicle independently..."

Fuel & Propulsion System ODI #11757244
Filed: 08/16/2026
Defect Report

"I took my vehicle in for the safety recall due to an expanding fuel tank on 08/03/2026. I received my vehicle back on 8/12/2026. Hyundai performed an improper repair on the vehicle that will not correct the fuel tank expansion. They replaced the same check valve that was replaced last time I..."

Fuel & Propulsion System ODI #11755570
Filed: 08/07/2026
Defect Report

"Gas tank expansion and pcv melted. Car smells like gas when I was driving earlier, and my garage was flooded with the fumes of gasoline."

Electrical System ODI #11755451
Filed: 08/07/2026
Defect Report

"The Left blinker switch keeps going in and out, working about 50% of the time. Both the light and the blinker sound do not turn on. When getting it checked out at an auto repair shop, the maintenance tech said this was more and more common for 2021 sonatas and it was not due to anything I did. It..."

Engine & Cooling ODI #11755133
Filed: 08/05/2026
Defect Report

"The vehicle experiences sudden, complete electrical power loss while driving at speed on highways and city streets or on the parking. All digital displays turn off, the engine shuts down, and power-assisted steering and braking are instantly lost without prior warning, presenting an extreme..."

Multi-Year Trend

Complaint History for Hyundai Sonata

Reported defect complaint volume across sibling model years (2015–2026)

Model Year NHTSA Complaints Crash Reports Safety Recalls Detailed Report
2015 Hyundai Sonata 1192 38 12 View 2015 Problems →
2016 Hyundai Sonata 850 23 8 View 2016 Problems →
2017 Hyundai Sonata 840 29 4 View 2017 Problems →
2018 Hyundai Sonata 378 18 1 View 2018 Problems →
2019 Hyundai Sonata 163 9 0 View 2019 Problems →
2020 Hyundai Sonata 189 5 4 View 2020 Problems →
2021 Hyundai Sonata Current Page 182 8 4 Current
2022 Hyundai Sonata 110 8 3 View 2022 Problems →
2023 Hyundai Sonata 100 8 2 View 2023 Problems →
2024 Hyundai Sonata 54 1 1 View 2024 Problems →
2025 Hyundai Sonata 27 1 0 View 2025 Problems →
2026 Hyundai Sonata 0 0 1 View 2026 Problems →
Exhaustive System Audit

Detailed NHTSA Component Breakdown for 2021 Hyundai Sonata

Complete distribution of consumer defect reports across all 49 granular NHTSA system and subsystem classifications

Vehicle Component / System Total Complaints Crash Reports Fire Reports Injury Entries Fatality Entries
Electrical System NHTSA category: ELECTRICAL SYSTEM 27 0 0 0 0
Engine NHTSA category: ENGINE 24 1 0 0 0
Other / Uncategorized NHTSA category: UNKNOWN OR OTHER 24 1 0 0 0
Powertrain NHTSA category: POWER TRAIN 13 0 0 0 0
Fuel System NHTSA category: FUEL SYSTEM, GASOLINE 10 0 0 0 0
Fuel & Propulsion System NHTSA category: FUEL/PROPULSION SYSTEM 9 0 0 0 0
ELECTRICAL SYSTEM,ENGINE 7 0 0 0 0
POWER TRAIN,ENGINE 6 0 0 0 0
ENGINE,FUEL/PROPULSION SYSTEM 5 0 0 0 0
Engine & Cooling NHTSA category: ENGINE AND ENGINE COOLING 4 0 0 0 0
Visibility & Wipers NHTSA category: VISIBILITY/WIPER 4 0 0 0 0
UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM 3 1 0 5 0
Visibility / Glass NHTSA category: VISIBILITY 3 0 0 0 0
ELECTRICAL SYSTEM,UNKNOWN OR OTHER 2 0 0 0 0
FUEL SYSTEM, GASOLINE,ENGINE 2 0 0 0 0
POWER TRAIN,ELECTRICAL SYSTEM 2 0 0 0 0
POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM 2 0 0 0 0
SERVICE BRAKES,FORWARD COLLISION AVOIDANCE 2 1 0 0 0
Structure & Body NHTSA category: STRUCTURE 2 0 0 0 0
UNKNOWN OR OTHER,ENGINE 2 0 0 0 0
Air Bags NHTSA category: AIR BAGS 1 1 0 0 0
AIR BAGS,FORWARD COLLISION AVOIDANCE 1 1 0 7 0
AIR BAGS,FORWARD COLLISION AVOIDANCE,LANE DEPARTURE 1 0 0 0 0
AIR BAGS,SEATS 1 0 0 0 0
ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM 1 0 0 0 0
ELECTRICAL SYSTEM,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
ELECTRICAL SYSTEM,STRUCTURE,VISIBILITY/WIPER 1 0 0 0 0
ENGINE,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
ENGINE,FUEL/PROPULSION SYSTEM,VISIBILITY/WIPER 1 0 0 0 0
ENGINE,VISIBILITY/WIPER 1 0 0 0 0
Forward Collision Avoidance NHTSA category: FORWARD COLLISION AVOIDANCE 1 1 0 2 0
FUEL/PROPULSION SYSTEM,VISIBILITY/WIPER,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
PARKING BRAKE,UNKNOWN OR OTHER 1 1 0 0 0
POWER TRAIN,UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM 1 0 0 0 0
POWER TRAIN,VEHICLE SPEED CONTROL 1 0 0 0 0
Seat Belts NHTSA category: SEAT BELTS 1 0 0 0 0
SEAT BELTS,UNKNOWN OR OTHER 1 0 0 0 0
Seats & Restraints NHTSA category: SEATS 1 0 0 0 0
Service Brakes NHTSA category: SERVICE BRAKES 1 0 0 0 0
STEERING,ELECTRICAL SYSTEM 1 0 0 0 0
STEERING,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
STRUCTURE,UNKNOWN OR OTHER 1 0 0 0 0
STRUCTURE,VISIBILITY 1 0 0 0 0
SUSPENSION,ENGINE,LANE DEPARTURE 1 0 0 0 0
Tires NHTSA category: TIRES 1 0 0 0 0
UNKNOWN OR OTHER,ENGINE,VISIBILITY/WIPER 1 0 0 0 0
UNKNOWN OR OTHER,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
UNKNOWN OR OTHER,LANE DEPARTURE,FORWARD COLLISION AVOIDANCE 1 0 0 0 0
VEHICLE SPEED CONTROL,ENGINE 1 0 0 0 0
Search Intelligence

Quick Answers: Common Problems & Reliability Questions for the 2021 Hyundai Sonata

Direct, deterministic answers synthesized from verified United States government databases for the 2021 Hyundai Sonata

What are the most common reported problems with the 2021 Hyundai Sonata?

In official NHTSA consumer records, the most frequently cited issue area for the 2021 Hyundai Sonata is Engine & Cooling, appearing in 48 records (26.4% of submitted filings).

Secondary reported categories include Electrical System (42) and Fuel & Propulsion System (35).

Source: NHTSA Office of Defects Investigation (ODI)

Is the 2021 Hyundai Sonata a reliable vehicle?

AutoUtility does not issue subjective reliability scores or commercial ratings. In official United States government records, NHTSA tracks 182 consumer defect complaints and 4 safety recall campaigns for the 2021 Hyundai Sonata.

Reviewing documented component complaint distributions, recall remedy notices, and active federal investigations provides an objective, evidence-based view of the vehicle's historical safety and defect record.

Source: NHTSA ODI & Safety Recalls Databases

Are there crash, fire, or injury reports associated with the 2021 Hyundai Sonata?

Among consumer complaint records on file with NHTSA for the 2021 Hyundai Sonata, 8 filings cite a crash, 0 cite smoke or fire, and 3 report one or more injuries.

Incident entries represent consumer descriptions at the time of submission to federal authorities and do not establish mechanical causation or legal liability.

Source: NHTSA Office of Defects Investigation Consumer Logs

Has NHTSA formally investigated defects on the 2021 Hyundai Sonata?

NHTSA ODI records list 2 formal defect investigations involving the 2021 Hyundai Sonata (all closed).

Federal defect investigations are formal engineering evaluations opened when safety defect trends emerge, and do not by themselves establish a confirmed defect or mandatory recall.

Source: NHTSA Office of Defects Investigation Registry
Official US Government Data Provenance

The complaint records on this page are retrieved directly from the NHTSA Office of Defects Investigation (ODI) public database under 49 CFR Part 576.

Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.