Service bulletin 23-01-093H

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10247604
Published by NHTSA	2023-12-22
Manufacturer's number	23-01-093H
Manufacturer's date	2023-12-15
NHTSA component	ELECTRICAL SYSTEM; POWER TRAIN

NHTSA's summary

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).

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Electrical system, Transmission and driveline

Vehicles listed
HYUNDAI SONATA HYBRID	2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it)

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
23V526000	2023-07-27. POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:PUMP
2022568	2022-10-06. Powertrain
22V746000	2022-10-06. POWER TRAIN:AUTOMATIC TRANSMISSION
20V213000	2020-04-09. ELECTRICAL SYSTEM:SOFTWARE

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
26-AT-005H TSB	2026-06-16. Service bulletin. 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. The correct TCU software update must be matched with the correct corresponding 8WDCT hardware, otherwise, drivability concerns may occur. This service procedure should be performed prior to any 8WDCT replacements done for drivability/judder concerns.
26-GI-002H TSB	2026-06-06. Service bulletin. This bulletin provides information related to the navigation and head unit software changes introduced in the 2026 1st Navigation Map and Software Update. The changes may vary depending on vehicle type, model, and navigation system. Refer to the 2026 1st Navigation Map and Software Update Key Improvements and Additional Improvements tables in this TSB for a list of specific changes. The software can be downloaded via Navigation Updater (NAU) and updated by USB.
26-EE-003H TSB	2026-04-21. Service bulletin. 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.
26-AT-001H TSB	2026-03-11. Service bulletin. 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.
25-BE-020H TSB	2025-10-03. Service bulletin. 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	2025-08-22. 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	2025-07-22. 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	2025-07-22. 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.
25-01-045H TSB	2025-07-15. Service campaign. A software update is available for multiple vehicles equipped with either Display Audio 2.0V or the AVN 5th Gen Wide system.
25-AT-001H TSB	2025-06-03. Service bulletin. 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.