Service bulletin SC345_TSB

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	11022351
Published by NHTSA	2025-09-02
Manufacturer's number	SC345_TSB
Manufacturer's date	2025-08-20
Campaign id or software version	SC345
NHTSA component	POWER TRAIN

NHTSA's summary

TECHNICAL SERVICE BULLETIN: VOLUNTARY SERVICE CAMPAIGN FRONT MOTOR REDUCTION GEAR OIL REPLACEMENT (SC345) - This bulletin provides information to replace the front motor reduction gear assembly gear oil on certain 2023-2024MY Niro EV (SG2 EV) vehicles produced from December 12, 2022 through February 7, 2024 and EV6 (CV) vehicles produced from December 14, 2022 through February 22, 2024. During the production of the subject vehicles, the amount of gear oil in the front motor and reduction gear assembly may have been filled below factory specification. If the gear oil level is lower than Kia’s factory specifications, the subject vehicles may eventually produce a grinding noise or whining noise from the front of the vehicle while driving.

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

Transmission and driveline

Vehicles listed
KIA EV6	2023, 2024
KIA NIRO EV	2023, 2024 (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
24V271000	2024-04-16. POWER TRAIN:DRIVELINE:DIFFERENTIAL UNIT
2024054	2024-01-31. Powertrain
24V057000	2024-01-31. POWER TRAIN:DRIVELINE:DRIVESHAFT

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
SC345Z_TSB	2025-10-17. Service bulletin. TECHNICAL SERVICE BULLETIN: SUBSEQUENT REPAIR ACTION: FRONT MOTOR REDUCTION GEAR ASSEMBLY REPLACEMENT (SC345Z) - This bulletin provides information regarding grinding or whining noise coming from the front motor reduction gear assembly after replacing the oil under SC345 (published in August 2025) on certain 2023-2024MY Niro EV (SG2 EV) vehicles produced from December 12, 2022 through February 7, 2024 and EV6 (CV) vehicles produced from December 14, 2022 through February 22, 2024. In rare cases, the front motor reduction gear assembly may exhibit noise after having the oil replaced.
SC345_QA	2025-08-20. Service campaign. VOLUNTARY SERVICE CAMPAIGN: QUESTION AND ANSWER (SC345) - This document is the Question and Answer Guide containing the most frequently asked questions regarding the Voluntary Service Campaign SC.
SC345_OWNR_SG2	2025-08-20. Service campaign. VOLUNTARY SERVICE CAMPAIGN: OWNER NOTIFICATION (SC345) - This document is the owner notification advising that Kia is conducting a Voluntary Service Campaign to replace the gear oil in the front motor and gear reduction assembly, and fill it to the factory-specified amount in certain Niro EV vehicles, manufactured from December 12, 2022 through February 7, 2024.
SC345_OWNR_CV	2025-08-20. Service campaign. VOLUNTARY SERVICE CAMPAIGN: OWNER NOTIFICATION (SC345) - This document is the owner notification advising that Kia is conducting a Voluntary Service Campaign to replace the gear oil in the front motor and gear reduction assembly, and fill it to the factory-specified amount in certain 2023-2024MY EV6 vehicles, manufactured from December 14, 2022 through February 22, 2024.
SC345_DPSM	2025-08-20. Service campaign. VOLUNTARY SERVICE CAMPAIGN: DEALER PARTS AND SERVICE MANAGER MEMO (SC345) - This document is the announcement to the dealer Parts and Service managers advising that Kia is conducting a Voluntary Service Campaign to replace the gear oil in the front motor and gear reduction assembly, and fill it to the factory-specified amount in certain 2023-2024MY EV6 vehicles, manufactured from December 14, 2022 through February 22, 2024 and Niro EV vehicles, manufactured from December 12, 2022 through February 7, 2024.
SC345_DP	2025-08-20. Service campaign. VOLUNTARY SERVICE CAMPAIGN: DEALER PRINCIPAL MEMO (SC345) - This document is the announcement to the dealer principals advising that Kia is conducting a Voluntary Service Campaign to replace the gear oil in the front motor and gear reduction assembly, and fill it to the factory-specified amount in certain 2023-2024MY EV6 vehicles, manufactured from December 14, 2022 through February 22, 2024 and Niro EV vehicles, manufactured from December 12, 2022 through February 7, 2024.
TSB_TRA046_R5	2025-04-23. Service bulletin. TECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced, and the transmission oil cooler is transferred to the new transmission.
TSB_TRA046_R4	2024-06-04. Service bulletin. This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced.
TSB_TRA110	2024-05-06. Service bulletin. TECHNICAL SERVICE BULLETIN: 6DCT MIL ON DTC (P073F73) LOGIC & LEARNING FUNCTION IMPROVEMENT - This bulletin provides information to upgrade the Dual Clutch Transmission (DCT) software logic on some 2024MY Niro P/HEV (SG2 P/HEV) produced from October 18, 2023 through November 18, 2023. The affected vehicles may exhibit a MIL 'ON' with DTC P073F73 and, in some cases, engage 2nd gear while accelerating from a stop instead of 1st gear.
PS750	2023-10-01. Service bulletin. PITSTOP: AWD SYSTEM CONCERN DUE TO TIRE CIRCUMFERENCE - This Pitstop provides information regarding potential concerns with the All-Wheel-Drive (AWD) system due to tire sizes of differing circumference. Some customers may complain of a chatter sensation felt in the drivetrain of the vehicle and/or the failure of drivetrain component(s). A difference in tire size (width, aspect ratio, construction, rim diameter etc.) may be the cause.