Kia bulletin SC345Z
What it saysSUBSEQUENT 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… NHTSA’s full summary ↓
Kia filed this with NHTSA as a service bulletin dated Oct 9, 2025, received Oct 17, 2025, about the power train — 1 document under this number: SC345Z_TSB. It names 4 model years (2023–2024). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
Get the next Kia bulletin for your model by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationWhat it applies to, as the document itself states it — the build window in the manufacturer’s own words, read by machine from the PDF NHTSA serves. The build date is on the certification label in the driver’s door jamb; the dealer settles a borderline vehicle by its VIN.
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.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| SC345Z_TSB | Service bulletin | Oct 9, 2025 | 11024346 | PDF, 412 KB |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themA vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Email me new Kia bulletins for one of these models
A weekly email, sent only in a week when Kia files something new with NHTSA for the model you pick — service bulletins, campaigns, warranty extensions, over-the-air notices, every model year. Nothing else is sent; one-click unsubscribe in every message. Separate from recall alerts.
What owners reported
Source: NHTSA complaint databaseOwners of the 4 model years this bulletin names have filed 300 complaints with NHTSA since 2015. 53 of them name Power Train — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
The vehicle is a rental vehicle. It experienced two incidents of sudden loss of propulsion within the first two days of operation. During both events, the vehicle became completely unresponsive to accelerator pedal input and would not move despite being placed in Drive.
2023 Kia Niro · Power Train · filed with NHTSA Feb 21, 2026 · ODI 11719665
The contact owns a 2024 Hyundai Niro Hybrid. The contact stated that while at a stop light the warning message "transmission overheating" had displayed and the vehicle did not drive forward.
2024 Kia Niro · Power Train · filed with NHTSA May 18, 2026 · ODI 11738543
Heard a pop, followed by power failure and warning lights to stop operating the vehicle. The ICCU unit had blown
2024 Kia EV6 · Power Train · filed with NHTSA Jan 1, 2026 · ODI 11708251
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the power train
Source: same model, same component group5 other manufacturer communications filed against these Kia models under the same component group (power train), newest first.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| SC345 | Service campaign | Aug 22, 2025 | TECHNICAL SERVICE BULLETIN: VOLUNTARY SERVICE CAMPAIGN FRONT MOTOR REDUCTION GEAR OIL REPLACEMENT (SC345) - This bulletin provides informati… |
| TSB_TRA046_R5 | Service bulletin | Apr 17, 2025 | TECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - This bulletin has been revised to include additional information. New/rev… |
| TSB_TRA046_R4 | Service bulletin | May 16, 2024 | This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush… |
| TSB_TRA110 | Service bulletin | Apr 29, 2024 | TECHNICAL SERVICE BULLETIN: 6DCT MIL ON DTC (P073F73) LOGIC & LEARNING FUNCTION IMPROVEMENT - This bulletin provides information to upgrade… |
| TSB_TRA046_R3 | Service bulletin | Nov 18, 2022 | TECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - This bulletin provides information relating to the correct transmission f… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Kia, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Kia SC345Z a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the SC345Z repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every Kia warranty extension on file lists the ones Kia has filed.
Which vehicles does SC345Z cover?
The manufacturer filed it against 4 model years: 2024 Kia EV6, 2023 Kia EV6, 2024 Kia Niro, 2023 Kia Niro. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone. The document itself sets the build window: 2023-2024MY Niro EV (SG2 EV): built 12 Dec 2022 – 7 Feb 2024; 2023-2024MY Niro EV (SG2 EV): built 14 Dec 2022 – 22 Feb 2024; Niro EV (SG2 EV): built 12 Dec 2022 – 7 Feb 2024 — the build date is on the certification label in the driver’s door jamb.