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Service bulletins for the 2018 Hyundai Sonata

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

240 on file from NHTSA, as of 2026-10-19.

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By component

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Bulletins, newest first
20-FL-003H2020-06-06. Service bulletin. ENGINE AND ENGINE COOLING. Certain 2016-2019 Sonata Hybrid (LF HEV) vehicles may experience check engine light illumination with DTC P0456 - Evaporative System (EVAP) - Very Small Leak stored. Salt particulate deposit can form inside the Natural Vacuum Leak Detection (NVLD) sensor which may cause intermittent operation prompting the DTC P0456 and check engine light. This bulletin provides the procedure to replace the NVLD sensor with an updated Air Filter Kit to help prevent entry of the salt particulates.
20-01-020H2020-06-06. Service bulletin. ENGINE AND ENGINE COOLING. Certain 2016-2019 Sonata Hybrid (LF HEV) may experience check engine light illumination with DTC P0456 - Evaporative System (EVAP) - Very Small Leak stored. These conditions primarily occur in the California coastal areas that are subject to marine layer cloud cover. Salt particulate deposit can form inside the Natural Vacuum Leak Detection (NVLD) sensor which may cause intermittent operation prompting the DTC P0456 and check engine light. This bulletin provides the procedure to install a new Air Filter Kit with an updated filter to help prevent entry of the salt particulates. In addition, replace NVLD sensor if DTC P0456 found stored in the Engine Control Module (ECM).
20-SS-002H(1)2020-06-06. Service bulletin. WHEELS; TIRES. This bulletin provides information on tire maintenance best practices and procedures for dealers and customers to maximize tire life and performance.
20-BD-007H-12020-06-06. Service bulletin. EQUIPMENT. This bulletin describes the general guidelines to help disinfect and protect vehicle exterior/interior surfaces using recommended safe chemical products.
20-EE-003H2020-05-07. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This bulletin provides information on identifying dealer stock vehicles with either: • A Battery SOC alert - low Battery State of Charge (SOC) at or below 50%. • A 30 Day alert - vehicle has not started and reported an SOC in 30 days.
20-AT-016H2020-05-07. Service bulletin. POWER TRAIN; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; EQUIPMENT ADAPTIVE/MOBILITY. The automatic transmission warranty repair policy authorizes in-dealership repairs of the following components for both OEM (new) and remanufactured automatic transmissions:
20-AT-014H2020-05-07. Service bulletin. POWER TRAIN; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. If you are servicing an applicable vehicle with a “Check Engine” light on and one or more of the DTC listed below, follow the repair procedure and replace the related solenoid and oil pressure harness.
20-HA-001H2020-04-07. Service bulletin. SERVICE BRAKES, AIR:SUPPLY:COMPRESSOR. This bulletin provides additional service diagnostic information and repair procedures related to electric A/C compressors equipped in hybrid electric vehicles, plug-in hybrid electric vehicles, and electric vehicles.
20-AT-011H2020-04-07. Service bulletin. SERVICE BRAKES, AIR:ANTILOCK:WHEEL SPEED SENSOR. If you are servicing an applicable vehicle with a “Check Engine” light on and one or more of the DTC listed below, follow the repair procedure and replace the related solenoid and oil pressure harness.
20-BD-007H2020-04-07. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY. This bulletin describes the general guidelines to disinfect and protect vehicle interior surfaces using certain safe chemical products.
20-EE-002H(1)2020-04-07. Service bulletin. ELECTRICAL SYSTEM. This bulletin describes the mandatory procedure to submit battery test data electronically for battery warranty claims by running the GDS Battery Claim App. The App must be run right after an incident battery is removed from the vehicle or after a battery charge is completed which qualifies for a warranty. It must be run at any time between RO open and close dates.
Campaign T3G DBP2020-03-07. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. Applicable vehicles with 2.0L Turbo and 2.4L GDI engines may experience the Check Engine warning lamp illuminated with DTC P1326. Follow the procedures on TSB #20-01-004H (supersedes TSB #19-01-006H-4) rotate the crankshaft, perform the bearing inspection (if crankshaft does rotate) and/or replace the engine based on the crankshaft/bearing inspection results.
20-AT-008H2020-03-07. Service bulletin. POWER TRAIN; EQUIPMENT; ELECTRICAL SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY. If you are servicing an applicable vehicle with a “Check Engine” light on and one or more of the DTC listed below, follow the repair procedure and replace the related solenoid and oil pressure harness.
20-01-004H - The2020-03-07. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING; EQUIPMENT; ELECTRICAL SYSTEM:SOFTWARE. Applicable vehicles with 2.0L Turbo and 2.4L GDI engines may experience the Check Engine warning lamp illuminated with DTC P1326. Follow the procedure to inspect the vehicle and replace the engine or update the engine ECU software based on the inspection results.
20-01-006H2020-03-07. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING. Hyundai is conducting a product improvement campaign to enhance the knock sensor software to detect abnormal engine bearing noise before potentially severe engine damage occurs. If abnormal engine bearing noise is detected, the Malfunction Indicator Lamp (MIL) will blink continuously, a chime will sound on certain vehicles, and the vehicle will be placed in Engine Protection Mode allowing the customer to drive to the nearest Hyundai dealer for diagnosis and repair. In addition, DTC P132600 will be recorded in the ECM. The vehicle can continue to be operated for a limited time in Engine Protection Mode, but it will accelerate slower and have a reduced maximum speed. Engine RPMs will be limited to approximately 1800-2000 RPM.
Campaign 953 Dea2020-03-07. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ELECTRICAL SYSTEM:SOFTWARE. Hyundai has developed a new engine monitoring technology called a Knock Sensor Detection System (KSDS). The technology uses software innovations and leverages existing engine sensors to continuously monitor for symptoms that may precede an engine failure. Watch this video to learn more. The KSDS software continuously monitors engine vibrations for unusual patterns that develop as an engine connecting rod bearing wears abnormally that could later cause engine seizure. If vibrations caused by bearing wear start to occur, the malfunction indicator lamp will blink continuously, an audible chime will sound and the vehicle will be placed in a temporary engine protection mode with reduced power and acceleration. At that time, Diagnostic Trouble Code (DTC) P1326 will be recorded in the ECM. In addition, Hyundai will extend the warranty to 10 years and 120,000 miles (up from 100,000 miles) for original and subsequent owners of the covered vehicles for engine repairs needed because of excessive connecting rod bearing damage.
20-BR-001H2020-03-06. Service bulletin. SERVICE BRAKES, HYDRAULIC. This bulletin describes the procedure to properly bleed the brakes on Sonata HEV/PHEV (LF) and Ioniq EV/HEV/PHEV (AE) vehicles. This procedure applies when any air is introduced into the Active Hydraulic Boost (AHB) system, which consists of the pressure supply unit (PSU), and the integrated brake actuation unit (IBAU). Improper bleeding of the brake system can result in the presence of air, which may reduce braking effectiveness.
20-SS-001H2020-03-06. Service bulletin. SUSPENSION. This bulletin describes the requirements for all wheel alignment and/or vehicle tracking claims and best practices when diagnosing and conducting alignment-related repairs for all models and model years.
20-AT-001H2020-02-03. Service bulletin. POWER TRAIN. This TSB provides a procedure to diagnose and repair a transaxle for the following Incorrect Ratio DTC (transaxle clutch slipping more than 200 rpm in gear).
20-ST-001H2020-02-03. Service bulletin. STEERING. This bulletin provides information regarding replacement of the column-mounted Motor Driven Power Steering (MDPS) system as separate components.
20-AT-003H2020-02-03. Service bulletin. ENGINE AND ENGINE COOLING. If you are servicing an applicable vehicle with a Check Engine light on and one or more of the DTC listed below, follow the repair procedure and replace the related input/output speed sensor and oil pressure harness.
20-AT-004H2020-02-03. Service bulletin. ENGINE AND ENGINE COOLING. If you are servicing an applicable vehicle with a Check Engine light on and one or more of the DTC listed below, follow the repair procedure and replace the related oil pressure harness with integrated oil temperature sensor.
20-AT-005H2020-02-03. Service bulletin. ENGINE AND ENGINE COOLING. If you are servicing an applicable vehicle with a Check Engine light on and one or more of the DTC listed below, follow the repair procedure and replace the related solenoid and oil pressure harness.
20-BE-001H2020-02-03. Service bulletin. ELECTRICAL SYSTEM. This bulletin provides guidelines to inspect the USB, head unit, and multi-box for common connection conditions. 2. This bulletin presents guidelines to inspect for common Android Auto and Apple CarPlay connection conditions. 3. This bulletin provides physical differences between the USB 2.0 port and USB 3.0 port.
19-AT-021H-12020-01-21. Service bulletin. POWER TRAIN; EQUIPMENT. If you are servicing a vehicle with a transmission slipping concern, follow the Service Procedure shown below and perform a stall test. This TSB provides a procedure to test each clutch in the transmission. If the vehicle fails the stall test, replace the transmission. ? PASS: Stall speed is between 1700~2900 rpm (See shop manual for stall speed). ? FAIL: Engine revs to redline limit (6,000~6,500 rpm). If so, replace the transmission.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.