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Service bulletins for the 2020 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.

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

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By component

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Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
21-EM-004H2021-04-07. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. 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-EM-003H2021-04-06. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. This bulletin provides the inspection procedure and repair guidelines for certain vehicles listed below.
21-01-009H2021-03-05. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM:SOFTWARE. This bulletin provides information related to an Electronic Control Module (ECM) software update which revises detection logic for DTC P2422: EVAP System Restricted Vent Valve logic.
Campaign T5A Dea2020-07-08. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM:SOFTWARE. This service campaign information is related to an Electronic Control Module (ECM) software update to revise the logic for DTC P030X: Cylinder “X” Misfire Detected and P0456: EVAP System Leakage Detected – Very Small Leak. This Service Campaign T5A will replace Service Campaign T4N.
20-01-027H2020-07-08. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT; ENGINE AND ENGINE COOLING. This bulletin provides information related to an Electronic Control Module (ECM) software update to revise the logic for DTC P030X: Cylinder “X” Misfire Detected and P0456: EVAP System Leakage Detected – Very Small Leak.
20-FL-004H2020-06-06. Service bulletin. SERVICE BRAKES, HYDRAULIC; ENGINE AND ENGINE COOLING; POWER TRAIN. This bulletin describes the Idle Stop and Go (ISG) system operation, diagnostic and battery sensor recalibration procedure. Refer to applicable Shop Manual and Owner’s Manual for additional information.
20-AT-006H2020-03-07. Service bulletin. POWER TRAIN; ENGINE. 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.
Campaign T4N Dea2020-03-06. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. This service campaign provides information related to an ECM software update to revise the logic for DTC P0456: EVAP System Leakage Detected Very Small Leak.
20-01-005H(1)2020-03-06. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. This bulletin provides information related to an Electronic Control Module (ECM) software update to revise the logic for DTC P0456: EVAP System Leakage Detected Very Small Leak.
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.

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