2021 Hyundai Sonata Technical Service Bulletins

90 technical service bulletins (TSBs) are on record for the 2021 Hyundai Sonata. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11038458Oct 8, 2026Engine. Some vehicles equipped with internal combustion engines may exhibit higher-than-expected engine oil consumption. This bulletin outlines the combustion chamber cleaning procedure for vehicles diagnosed with this condition.
• 11038456Oct 7, 2026Engine. Certain vehicles equipped with internal combustion engines may exhibit higher-than-expected engine oil consumption. This bulletin provides the inspection and repair procedures for vehicles exhibiting this condition. All internal combustion engines consume engine oil as part of normal engine operation. Oil consumption rates may vary based on mileage, operating conditions, driving habits, and maintenance history.
• 11033840Jun 5, 2026Transmission and drivetrain. This bulletin provides information related to a Transmission Control Unit (TCU) software update for some vehicles equipped with an 8-speed wet dual clutch transmission (8WDCT). The software update revises the touch point learning variation, improving drivability and judder symptoms. Some 8WDCTs (indicated by a new part number) received an updated clutch spring.
• 11031400Apr 18, 2026Engine, Electrical system. Some vehicles may exhibit difficulty starting in cold weather. This bulletin provides the procedure to perform an inspection on the starter magnetic switch for potential freezing and, if necessary, replace the starter magnetic switch (solenoid) assembly.
• 11032523Apr 10, 2026Air bags. 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…
• 11032522Apr 10, 2026Air bags. 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…
• 11029937Mar 3, 2026Transmission and drivetrain. Some Santa Cruz (NXT), Santa Fe (TMA, MX5A), and Sonata (DN8A) models may require replacement of the 8-speed wet dual clutch transmission (8WDCT) when the vehicle sets one of the high pressure electric oil pump (HP EOP) DTCs listed below. This bulletin provides instructions to replace the 8WDCT.
• 11029906Feb 25, 2026Forward collision avoidance, Exterior lighting, Lane departure. Some 2019MY and newer vehicles equipped with a front view camera may illuminate certain warning lights and trigger DTC C272246 fault code for the front camera. In the following cases, the front camera auto-calibration range may be exceeded while driving: • If the front camera is not properly installed and is completely or partially detached.
• 11028666Feb 5, 2026Engine. Some Sonata (DN8, DN8A) vehicles may have DTCs P218100, P2181F0, and/or P2181F1 (Cooling System Performance) set in the Engine Control Module, resulting in an illuminated Check Engine warning lamp. Follow the procedure in this TSB to replace the Integrated Thermal Management (ITM) module and update both the Engine Control Module (ECM) and Transmission Control Module (TCM) if applicable. Follow the flowchart in this…
• 11027589Jan 7, 2026Fuel system. Some vehicles equipped with a 2.5L GDI Theta III engine (non-Turbo) may exhibit one or more misfire DTCs due to the GDI fuel injectors leaking internally. This may be caused by internal filter breakage in the injector. Follow the procedure in this TSB to replace all 4 injectors on affected vehicles, using the kit in the Parts Information section.
• 11025476Nov 6, 2025Exterior lighting. 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…
• 11023692Sep 30, 2025Electrical system. 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.
• 11018891May 30, 2025Transmission and drivetrain. Certain Santa Fe (TMA) and Sonata (DN8/DN8A) vehicles equipped with 8-speed dual clutch transmissions (8DCT) may exhibit one of the DTCs listed below, related to the high pressure electric oil pump (HP EOP). Follow the procedures in this TSB to update the Transmission Control Unit (TCU) to the latest sensorless logic on affected vehicles, and then perform air bleeding and transmission learning.
• 11018876May 16, 2025Electrical system. 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…
• 11018575May 8, 2025Electrical system. 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.
• 11017474Apr 30, 2025Engine, Electrical system. Certain Sonata (DN8) and Sonata (DN8A) vehicles may experience issues with the air conditioning due to damaged wiring in the engine room junction box. This bulletin provides instructions to replace the multi-fuse, reroute the damaged wiring using the blower wiring kit, and replace the fuse label.
• 11017341Apr 25, 2025Electrical system. Certain Sonata (DN8) and Sonata (DN8A) vehicles may experience issues with the air conditioning due to damaged wiring in the engine room junction box. This bulletin provides instructions to replace the multi-fuse, reroute the damaged wiring using the blower wiring kit, and replace the fuse label.
• 11017111Apr 7, 2025Electrical system. 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.
• 11015936Mar 18, 2025Electrical system. 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.
• 11012819Jan 9, 2025Fuel system. Some vehicles equipped with a 2.5L GDI Theta III engine (non-Turbo) may exhibit one or more misfire DTCs due to the GDI injectors leaking internally. This may be caused by internal filter breakage in the injector. Follow the procedure in this TSB to replace all 4 injectors on affected vehicles, using the kit in the Parts Information section.
• 11012362Jan 3, 2025Fuel system. Certain 2021-2023MY Sonata (DN8) and 2020-2022MY Sonata (DN8A) vehicles may have DTC P0451 stored in the ECU. Follow this bulletin to inspect the check valve, fuel pump cover and fuel tank, and update the ECU. If necessary, replace the check valve and/or fuel tank based on inspection results. The ECU Upgrade contains a revised DTC P14EE00 which supersedes P0451.
• 11012361Jan 3, 2025Fuel system. Certain 2021-2023MY Sonata (DN8) and 2020-2022MY Sonata (DN8A) vehicles may have Diagnostic Trouble Code (DTC) P0451 (also known as DTC P14EE00) stored in the Electronic Control Unit (ECU). The California Air Resources Board has determined that these vehicles may be releasing air pollutants which exceed Federal and California standards.
• 11011830Dec 10, 2024Electrical system. The subject vehicles may have Diagnostic Trouble Code (DTC) P0451 stored in the ECU, which could cause the Check Engine Lamp to come on.
• 11010975Nov 14, 2024Fuel system. Certain 2021-2023MY Sonata (DN8) and 2020-2022MY Sonata (DN8A) vehicles may have Diagnostic Trouble Code (DTC) P0451 stored in the Electronic Control Unit (ECU). The California Air Resources Board has determined that these vehicles may be releasing air pollutants which exceed Federal and California standards.
• 11010974Nov 14, 2024Fuel system. Certain 2021-2023MY Sonata (DN8) and 2020-2022MY Sonata (DN8A) vehicles may have DTC P0451 stored in the ECU. Follow this bulletin to inspect the check valve, fuel pump cover and fuel tank, and update the ECU. If necessary, replace the check valve and/or fuel tank based on inspection results.
• 11006112Jul 23, 2024Engine. Certain 20-22MY Sonata (DN8a), 21-23MY Santa Fe (TMa), and 22-23MY Tucson (NX4a) vehicles may experience a warning lamp illumination for a diagnostic trouble code P2181 that is related to the Integrated Thermal Management Module (ITM). Follow the service procedure outlined in this bulletin to replace the ITM.
• 11006111Jul 19, 2024Electrical system. 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.
• 10253275Apr 9, 2024Transmission and drivetrain. This TSB provides a procedure to diagnose and replace, if necessary, an automatic transmission with Incorrect Ratio DTC (transmission clutch slip in gear above limit) listed on Page 2.
• 10251294Feb 29, 2024Transmission and drivetrain, Engine cooling. This bulletin provides the procedure to update the Engine Control Module (ECM) and/or the Transmission Control Module (TCM) for 2020-2023MY Sonata (DN8/DN8a) vehicles to improve operation of the Idle Stop and Go (ISG) system. Under certain circumstances the vehicle may not restart after the ISG system has engaged and requires a manual restart due to the lack of intake manifold pressure recovery.
• 10251293Feb 28, 2024Transmission and drivetrain. This bulletin provides the procedure for updating the automatic transmission TCU and ECU software (Santa Fe ONLY) to improve shift quality, judder with ISG enabled and hesitation when accelerating.
• 10251285Feb 14, 2024Visibility (wipers, defrost, mirrors). 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.
• 10249699Jan 10, 2024Electrical system. 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.
• 10245580Nov 10, 2023Transmission and drivetrain. This TSB provides information to diagnose the push button shifter operation.
• 10247189Oct 13, 2023Engine cooling. This bulletin provides important checkpoint guidelines when performing engine oil and filter change services.
• 10243340Sep 18, 2023Electrical system, Engine cooling. This bulletin is issued to provide the extended battery diagnosis procedure using GDS-M. This battery diagnosis function displays the various battery-related faults such as: • Internal short circuit • Battery deterioration • Malfunction of electronic parts • Insufficient battery charge • Normal battery • Charging defect Battery diagnosis uses the battery sensor history saved for the last 30 days and ICU…
• 10243329Sep 14, 2023Transmission and drivetrain. If you are servicing an 8-speed front-wheel-drive vehicle equipped with automatic transaxle with one or more of the DTC or symptoms listed below, refer to the Service Procedure to diagnose the condition.
• 10241891Aug 28, 2023Transmission and drivetrain. This bulletin outlines changes to the service procedure regarding the replacement of 8-speed wet dual clutch transmissions (8WDCT) and associated transmission control unit (TCU). These changes only apply to vehicles equipped with Theta 2.5T engines. Certain transmissions (indicated by a new part number) have received an improved clutch spring. The correct TCU software update must be matched with the correct…
• 10241890Aug 28, 2023Transmission and drivetrain. This bulletin provides information related to a Transmission Control Unit (TCU) software update for certain vehicles equipped with an 8-speed wet dual clutch transmissions (8WDCT) that improves the touch point learning variation. Certain 8WDCTs (indicated by a new part number) received an improved clutch spring. The correct TCU software update must be matched with the correct corresponding 8WDCT hardware, otherwise…
• 10241885Aug 25, 2023Transmission and drivetrain. If you are servicing an 8-speed vehicle with a “Check Engine” light on and one or more of the DTC listed, follow the service procedure and replace the related solenoid and harness.
• 10241875Aug 21, 2023Engine cooling. This bulletin provides warranty procedure for EGR Valve replacement related to DTC P0401 EGR Flow Insufficient on 2020 and 2021MY Sonata (DN8a) equipped with 2.5 GDI Vehicles.
• 10241796Aug 1, 2023Transmission and drivetrain. 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
• 10240089Jul 18, 2023Transmission and drivetrain, Engine cooling, Electrical system. If you are servicing an 8-speed DCT front-wheel-drive vehicle with the DTC or symptoms listed below, refer to the Service Procedure to diagnose the condition.
• 10240087Jul 17, 2023Equipment, Electrical system. 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.
• 10240084Jul 11, 2023Transmission and drivetrain. If you are servicing an 8-speed front-wheel-drive vehicle equipped with automatic transaxle with one or more of the DTC or symptoms listed below, refer to the Service Procedure to diagnose the condition.
• 10238377Jun 9, 2023Engine cooling. This bulletin provides the diagnostic procedure for the GDI injector(s) in certain 21-23MY Sonata, 21-22MY Santa Fe, certain 22MY Santa Cruz, and certain 21-23MY Tucson equipped with 2.5L GDI engines with one or more misfire DTC(s) due to internally leaking GDI injector(s)
• 10237183May 10, 2023Transmission and drivetrain. This bulletin provides service procedures to prevent possible moisture intrusion of the HP EOP (High Flow Electric Oil Pump) connector when servicing the 8-speed wet dual clutch transmission (8WDCT). If moisture enters the HF EOP connector, this can result in corrosion and insufficient connection of the terminals.
• 10237182May 9, 2023Transmission and drivetrain. This TSB applies only if Recall 236 or Service Campaign T8N has been performed and the 8 speed wet dual clutch transmission (8WDCT) replacement is necessary related due to high pressure electric oil pump (HP EOP) DTC’s P1C2D03 (HP EOP Motor Position Sensor), P193B79 - HP EOP Performance, P0868 - Transmission Fluid Pressure (TFP) Sensor – Low. Replace the 8WDCT under this bulletin.
• 10235566Apr 24, 2023Body and structure. 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.
• 10235344Apr 7, 2023Engine cooling. This bulletin provides the procedure to repair poor pin tension at joint connector JE102 in certain Sonata (1.6 T-GDI engine) with one or more DTC.
• 10235343Apr 7, 2023Engine cooling. This bulletin provides the procedure to repair poor pin tension at joint connector JE202 in certain Sonata (2.5L GDI engine) with one or more DTC.

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