Vehicle report

2021 HYUNDAI SONATA HYBRID

Service bulletins

46 bulletins

Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.

DTN DCS

Other

The National Highway Traffic Safety Administration (NHTSA) has issued an urgent safety advisory regarding dangerous, counterfeit driver‑side airbag inflators manufactured by Jilin Province Detiannuo Automobile Safety System Co., Ltd. (DTN), that have been identified in U.S. vehicles following prior crashes, theft, or non‑certified airbag replacements. These inflators are not approved for use, may rupture during deployment, and have caused serious injuries and fatalities. Please see attached announcement, provided by NHTSA, for more details.

DTN DL

Other

The National Highway Traffic Safety Administration (NHTSA) has identified the presence of substandard and dangerous driver’s-side airbag inflators manufactured by Jilin Province Detiannuo Automobile Safety System Co., Ltd. (DTN). These inflators were not supplied, approved, or authorized by the vehicle manufacturers and have primarily been found in vehicles that previously experienced a crash and underwent airbag replacement using non-genuine parts. These dangerous inflators have ruptured during deployment, posing a serious risk of injury or death due to metal fragments entering the vehicle cabin. To date, Hyundai is aware of three people who have died while driving a Hyundai vehicle with one of these substandard replacement airbag inflators that deployed in what likely would have been a survivable crash. NHTSA has issued a public advisory urging vehicle owners and service professionals to have vehicles inspected if there is reason to believe that a non-genuine replacement airbag may have been installed. Vehicles with salvage or rebuilt titles, prior airbag deployments, or unknown repair histories may present a higher risk. NHTSA strongly cautions against self-inspection by vehicle owners and recommends inspection by trained technicians.

25-EM-007H TSB

Service Bulletin/Repair Instructions

Some Elantra (CN7, CN7A), Kona (OS, SX2), and Sonata Hybrid (DN8 HEV) vehicles equipped with 2.0L engines may illuminate a warning lamp for DTC P218100 (Cooling System Performance) related to the Integrated Thermal-Management Module (ITM). Follow the service procedure in this bulletin to install a spring onto the thermostat within the ITM, in order to prevent premature opening, and perform an ECU software update on affected vehicles.

25-BD-012H TSB

Service Bulletin/Repair Instructions

This bulletin provides information regarding condensation related to the accumulated moisture in the headlamp, rear combination lamp, daytime running lamp (DRL), or fog lamp. This TSB illustrates the various causes of condensation inside the lamp assembly. Lamp assembly replacement is NOT necessary in most cases. This condition can be eliminated by turning on the lamps with the engine running for several minutes or during normal driving operation.

25-BE-020H TSB

Service Bulletin/Repair Instructions

This bulletin provides information related to the changes introduced in the 2025 1st Navigation Map and Software Update. The changes may vary depending on vehicle type, model, and navigation system as described in this TSB.

25-01-010H-1 9B4 OL

Service Campaign

Certain Hyundai vehicles may exhibit a warning light with Diagnostic Trouble Code (“DTC”) P1BB20 due to a battery over voltage condition.

25-01-010H-1 DN

Service Campaign

Certain Elantra Hybrid (CN7 HEV), Sonata Hybrid (DN8 HEV), and Tucson Hybrid (NX4 HEV) vehicles may exhibit a warning light due to DTC Code P1BB20 (12V Lithium Battery Cell Voltage High). The California Air Resources Board has determined that these vehicles may be releasing air pollutants which exceed Federal and California standards.

25-01-010H-1 TSB

Service Campaign

This bulletin provides the procedure to update the software for the Battery Management System (BMS) on certain Elantra Hybrid (CN7 HEV), Sonata Hybrid (DN8 HEV), and Tucson Hybrid (NX4 HEV) vehicles that may exhibit a warning light with DTC P1BB200 and enter Limp Mode.

25-BE-002H TSB

Service Bulletin/Repair Instructions

This bulletin provides information related to the changes introduced in the 2024 2nd Navigation Map and Software Update. The changes may vary depending on vehicle type, model, and navigation system. Refer to the 2024 2nd Navigation Map and Software Update Improvements section in this TSB for a list of specific changes. The software can be downloaded via Navigation Updater (NAU) and updated by USB. The NAU website is https://update.hyundai.com/US/EN/navigationUpdate. For certain models equipped with a relevant Bluelink package, the software may be downloaded and applied via OTA update.

25-01-024H-1 TSB

Service Campaign

Some vehicles may exhibit a loss of connectivity or interruptions in the middle of using Bluelink Service functions. This may be due to an irregular disconnection on Verizon’s communication network. Follow the procedure in this TSB to reestablish the connection via the AVN pinhole reset method.

25-01-024H EM

Service Campaign

Some vehicles may exhibit a loss of connectivity or interruptions in the middle of using Bluelink Service functions. This may be due to an irregular disconnection on Verizon's communication network. If you are experiencing issues with remote commands, or other Bluelink services, please see the instructions below to reestablish the connection via the AVN pinhole reset method.

25-01-024H TSB

Service Campaign

Some vehicles may exhibit a loss of connectivity or interruptions in the middle of using Bluelink Service functions. This may be due to an irregular disconnection on Verizon’s communication network. Follow the procedure in this TSB to reestablish the connection via the AVN pinhole reset method.

25-01-010H DN

Service Bulletin/Repair Instructions

Certain Elantra hybrid (CN7 HEV), Sonata hybrid (DN8 HEV), and Tucson hybrid (NX4 HEV) vehicles may exhibit a warning light due to DTC Code P1BB20 (12V Lithium Battery Cell Voltage High). Follow the procedure in TSB 25-01-010H (or latest version) to perform the update the Battery management System (BMS) software.

25-01-010H TSB

Service Campaign

This bulletin provides the procedure to update the software for the Battery Management System (BMS) on certain Elantra Hybrid (CN7 HEV), Sonata Hybrid (DN8 HEV), and Tucson Hybrid (NX4 HEV) vehicles that may exhibit a warning light with DTC P1BB20.

24-AT-001H-1

Service Bulletin/Repair Instructions

This bulletin provides the procedure for updating the automatic transmission TCU (Transmission Control Unit) software to improve shift quality, judder and hesitation when accelerating.

24-BE-001H-1

Service Bulletin/Repair Instructions

Some vehicles equipped with the AVN 5th Gen Wide system may exhibit a condition where the radio app crashes frequently when entering radio mode and/or displays a message that reads “Uneven Road Ahead, Drive carefully” on the cluster along with a warning sound. Follow the procedure outlined in this bulletin to update the AVN software to resolve this condition.

24-01-054H

Service Campaign

Certain Elantra hybrid (CN7 HEV), Sonata hybrid (DN8 HEV), and Tucson hybrid (NX4 HEV) vehicles may exhibit a warning light due to DTC Code P1BB20 (12V Lithium Battery Cell Voltage High). Follow the procedure in TSB 24-01-054H (or latest version) to perform the update the Battery management System (BMS) software.

SERVICE CAMPAIGN 9B4

Service Bulletin/Repair Instructions

This bulletin provides the procedure to update the software for the Battery Management System (BMS) on certain Elantra Hybrid (CN7 HEV), Sonata Hybrid (DN8 HEV), and Tucson Hybrid (NX4 HEV) vehicles that may exhibit a warning light with DTC P1BB20.

24-BD-001H

Service Bulletin/Repair Instructions

This bulletin contains information about the proper removal of the windshield wiper blade protective cover on all models. If the protective cover is not removed correctly, there is a possibility of the rubber insert and rail spring becoming partially separated on the inner side of the wiper blade, which could lead to poor wiping performance and/or possible scratching of the windshield glass. Follow the procedure in this bulletin to properly remove the windshield wiper blade protective cover on all new wiper blades.

23-01-093H

Service Bulletin/Repair Instructions

This bulletin provides the procedure to update the Hybrid Control Unit (HCU) and Dual Automatic Temperature Control (DATC) software to help improve coolant flow to the Exhaust Heat Recovery System (EHRS).

24-BE-001H

Service Bulletin/Repair Instructions

Some vehicles equipped with the AVN 5th Gen Wide system may exhibit a condition where the radio app crashes frequently when entering radio mode and/or displays a message that reads “Uneven Road Ahead, Drive carefully” on the cluster along with a warning sound. Follow the procedure outlined in this bulletin to update the AVN software to resolve this condition.

23-EM-009H

Service Bulletin/Repair Instructions

Certain 2020-2023MY Sonata Hybrid (DN8 HEV) vehicles may exhibit coolant leakage, engine overheating, and white smoke from the exhaust due to an internal leak at the Exhaust Heat Recovery System (EHRS) portion of the center muffler assembly. Follow the procedure outlined in this bulletin to repair this condition after confirming EHRS is leaking internally.

23-AT-006H-2

Service Bulletin/Repair Instructions

This TSB provides information to diagnose the push button shifter operation.

23-EM-005H

Service Bulletin/Repair Instructions

This bulletin provides important checkpoint guidelines when performing engine oil and filter change services.

23-HC-002H

Service Bulletin/Repair Instructions

This bulletin provides information related to the Engine Control Module (ECM) software update and coolant replacement for 2020-2023MY Sonata Hybrid (DN8 HEV) vehicles to improve the coolant filling mode by discharging air bubbles.

23-AT-006H-1

Service Bulletin/Repair Instructions

This TSB provides information to diagnose the push button shifter operation. If you are servicing a vehicle with any symptoms listed below or DTCs (listed on Page 2) , follow the Service Procedure on Page 3. SYMPTOMS: • “Shifter System Malfunction” displayed in the cluster • Won’t shift into or out of gear or won’t shift out of Park • Incorrect gear display in cluster and/or won’t start

23-BE-007H

Service Bulletin/Repair Instructions

This Service Information bulletin provides information on how to update the Apple Carplay software from Hyundai’s Navigation Updates page. The current version of Google Maps has 10 times the data transmission compared to the previous version. As a countermeasure, an update with a frame skip logic has been added to resolve the data congestion with Google Maps.

23-BD-007H

Service Bulletin/Repair Instructions

Hyundai applies a Paint Protection Film (PPF) on new vehicles before delivery to dealerships. It provides a barrier between the paint and contaminants, such as rail dust, acid rain, and industrial fallout. In rare cases, the paint can become clouded under the PPF. These spots are the result of moisture trapped between the PPF and the paint.

23-BD-002H

Service Bulletin/Repair Instructions

This bulletin provides information regarding condensation related to the accumulated moisture in the headlamp, rear combination lamp, daytime running lamp (DRL), or fog lamp. This TSB illustrates the various causes of condensation inside the lamp assembly. Lamp assembly replacement is NOT necessary in most cases. This condition can be eliminated by turning on the lamps with the engine running for several minutes or during normal driving operation.

22-AT-010H

Service Bulletin/Repair Instructions

If you are servicing an applicable vehicle with a “Check Engine” light on and one or more of the DTC listed below, follow the Service Procedure and replace the valve body internal harness and the input/output speed sensor.

22-EM-010H

Service Bulletin/Repair Instructions

Follow the guidelines outlined in this bulletin to inspect and clean or replace certain components of the engine intake system accordingly during engine short block or sub-assembly replacement.

22-GI-006H

Service Bulletin/Repair Instructions

Effective June 2, 2008, Federal Motor Vehicle Safety Standard 110 (FMVSS 110) established a threshold for correcting load carrying capacity information indicated on tire placards when vehicle weight has been increased before retail sale. This limit is the lesser of 1.5% of GVWR or 100 pounds. If the total added weight exceeds the lesser of the limit, a label must be added to the driver-side B-pillar within 25mm (1 inch) of the original tire placard.

22-AT-008H

Service Bulletin/Repair Instructions

If you are servicing an applicable vehicle with a “Check Engine” light on and one or more of the DTC listed below, follow the Service Procedure and replace the related solenoid and harness.

218/231 amend

Service Bulletin/Repair Instructions

Certain vehicles may develop a bearing noise within the Motor Driven Power Steering (MDPS) column worm shaft assembly. If bearing noise is heard, follow the procedure in this bulletin to replace the worm shaft bearing.

22-ST-005H

Service Bulletin/Repair Instructions

Certain vehicles may develop a bearing noise within the Motor Driven Power Steering (MDPS) column worm shaft assembly. If bearing noise is heard, follow the procedure in this bulletin to replace the worm shaft bearing.

Certain vehicles

Service Bulletin/Repair Instructions

If you are servicing an applicable vehicle with a “Check Engine” light on and one or more of the DTC listed below, follow the Service Procedure and replace the harness with an integrated oil temperature sensor.

22-AT-001H

Service Bulletin/Repair Instructions

This TSB provides a procedure to diagnose the push button shifter operation. If you are servicing a vehicle with any symptoms or DTC listed below, follow the Service Procedure, Page 2.

21-ST-003H

Service Bulletin/Repair Instructions

Certain vehicles may develop a bearing noise within the Motor Driven Power Steering (MDPS) column worm shaft assembly. If bearing noise is heard, follow the procedure in this bulletin to replace the worm shaft bearing

21-AT-009H

Service Bulletin/Repair Instructions

This TSB provides a procedure to diagnose the push button shifter operation.

21-AT-007H

Service Bulletin/Repair Instructions

If you are servicing an 8-speed front-wheel-drive vehicle with the DTC or symptoms listed below, refer to the Service Procedure to diagnose the condition.  DIAGNOSTIC TROUBLE CODES:  P070500 - Transmission range sensor circuit malfunction  P070512 - Transmission range sensor circuit malfunction  P070514 - Transmission range sensor circuit malfunction  P07051C - Transmission range sensor circuit malfunction  P070600 - Transmission range sensor circuit range/performance  P070661 - Transmission range sensor circuit range/performance  P070696 - Transmission range sensor circuit range/performance  SYMPTOMS:  Malfunction Indicator Light (MIL) illuminated  5th gear fail-safe  No gear indication in cluster  Intermittently won’t shift into D or R  Intermittently won’t shift out of Park  Intermittent ly no engine cr ank/no start in “P” or “N” with or without MIL or DTC.

21-01-040H

Service Bulletin/Repair Instructions

This bulletin describes the procedure to update the Shift Control Unit (SCU) for Shift-by-Wire vehicles (SBW). The update improves the display in the cluster.

21-EM-004H

Service Bulletin/Repair Instructions

This bulletin provides the service procedure for engine connecting rod bearing clearance testing. Perform the procedure outlined in this bulletin to fulfill the Bearing Clearance Test inspection requirements to determine next required steps.

21-BR-002H

Service Bulletin/Repair Instructions

This bulletin provides best practice recommendations when performing brake service procedures.

21-EM-003H

Service Bulletin/Repair Instructions

This bulletin provides the inspection procedure and repair guidelines for certain vehicles listed below.

21-BE-002H

Service Bulletin/Repair Instructions

This bulletin describes the procedure to update the radio software to help reduce the disconnection occurrences.

21-01-007H

Service Bulletin/Repair Instructions

When using Wireless CarPlay, the system may intermittently auto disconnect. When Wireless CarPlay is disconnected, a pop up message “Phone Not Responding. Please reconnect it and try again” will appear on the radio screen. This bulletin describes the procedure to update the radio software to help reduce the disconnection occurrences.

Reading this report

Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.