Kia service campaign SC335
What it saysVOLUNTARY SERVICE CAMPAIGN: BMS S/W LOGIC IMPROVEMENT FOR DTC P1BB2 (SC335) - This bulletin provides information to upgrade the Battery Management System ‘BMS’ software logic on certain 2023-2024MY Sportage HEV (NQ5… NHTSA’s full summary ↓
Kia filed this with NHTSA as a service campaign dated Jun 26, 2025, received Feb 26, 2025, about the electrical system — 6 documents under this number: SC335_TSB_CLSD, SC335A_OWNR, SC335_TSB, SC335_QA and 2 more. It names 4 model years (2023–2024). A service campaign is not a safety recall — there is no NHTSA campaign number and no federal requirement — but it is usually work the manufacturer pays for on the vehicles it names; the dealer checks the VIN against the manufacturer’s list.
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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: VOLUNTARY SERVICE CAMPAIGN: BMS S/W LOGIC IMPROVEMENT FOR DTC P1BB2 (SC335) - This bulletin provides information to upgrade the Battery Management System ‘BMS’ software logic on certain 2023-2024MY Sportage HEV (NQ5 HEV) vehicles produced from February 15, 2022 to October 28, 2023, and 2023-2024MY Niro HEV (SG2 HEV) vehicles produced from June 21, 2022 through February 6, 2023. Due to a software issue, the Battery Management System (BMS) may inadvertently overcharge the 12V Lithium battery. If the 12V Lithium battery becomes overcharged, the subject vehicles may experience a reduction in motive power accompanied by the ‘Check Hybrid System, Stop Safely’ warning message, Hybrid system warning lamp, Service warning lamp, Charging system warning lamp, and a rapid beeping sound for approximately ten (10) seconds. (Note: This Voluntary Service Campaign supersedes ELE318/SA553).
Trouble codes it names: P1BB2
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| SC335_TSB_CLSD | Service bulletin | Jun 26, 2025 | 11019891 | PDF, 131 KB |
| SC335A_OWNR | Service campaign | Feb 18, 2025 | 11014553 | PDF, 158 KB |
| SC335_TSB | Service bulletin | Feb 13, 2025 | 11014552 | PDF, 536 KB |
| SC335_QA | Service campaign | Feb 13, 2025 | 11014551 | PDF, 112 KB |
| SC335_DPSM | Service campaign | Feb 13, 2025 | 11014550 | PDF, 108 KB |
| SC335_DP | Service campaign | Feb 13, 2025 | 11014549 | PDF, 132 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.
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What owners reported
Source: NHTSA complaint databaseOwners of the 4 model years this bulletin names have filed 505 complaints with NHTSA since 2015. 149 of them name Electrical System, Fuel/Propulsion System — 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.
While navigating the highly dangerous downhill descent of the Tejon Pass, LEBEC, CA , the vehicle experienced a complete throttle disengagement. The accelerator pedal became entirely unresponsive, leaving the vehicle without power on a steep, high-speed highway descent. I was traveling with my young daughter inside the vehicle.
2024 Kia Sportage · Fuel/Propulsion System · filed with NHTSA Jun 22, 2026 · ODI 11745626
First of all, what I am about to write put my husband and I in great danger. Driving on a two way, busy, rural highway, traveling approximately 65 mph, my Kia suddenly displayed a warning to pull over immediately and something about the battery. I barely had time to pull on to a narrow shoulder before it completely died.
2024 Kia Sportage · Electrical System · filed with NHTSA Oct 6, 2026 · ODI 11769453
The 12-volt battery system in my 2024 Kia Niro (VIN: ) has suffered two total failures in under one year of ownership (approx. 10,000 miles). In both instances, the vehicle was completely unresponsive, with no power to essential systems. Safety Risks and Incidents: 1. : Vehicle experienced a total power loss.
2024 Kia Niro · Electrical System · filed with NHTSA Jan 7, 2026 · ODI 11709314
In depth: 2023 Kia Sportage electrical problems →
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 electrical system
Source: same model, same component group48 other manufacturer communications filed against these Kia models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Kia list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| TSB_CLI049_R2 | Service bulletin | Aug 28, 2026 | TECHNICAL SERVICE BULLETIN: PARTIAL REPAIR – ELECTRICAL A/C COMPRESSOR - This bulletin has been revised to include additional information. N… |
| TSB_ELE426 | Service bulletin | Aug 19, 2026 | TECHNICAL SERVICE BULLETIN: AVN GEN 5.0 WIDE SOFTWARE UPDATE - This bulletin provides information on the Audio Video Navigation (AVN) system… |
| CA2606 | Service bulletin | Jul 25, 2026 | TECHNICAL SERVICE BULLETIN: CUSTOMER ACTION: UPPER ACTIVE AIR FLAP DUCT ASSEMBLY REPLACEMENT (CA2606) - This bulletin provides information t… |
| PI2603Y | Service bulletin | Jul 8, 2026 | TECHNICAL SERVICE BULLETIN: BSA REPLACEMENT (PI2603Y) - This bulletin provides information related to the Technical Service Bulletin previou… |
| SA644 | Service bulletin | Jul 2, 2026 | TECHNICAL SERVICE BULLETIN: ON-BOARD CHARGER INSPECTION AND REPLACMENT (SA644) - This bulletin provides information related to charging syst… |
| PI2603 | Other | Jun 17, 2026 | TECHNICAL SERVICE BULLETIN: PRODUCT IMPROVEMENT CAMPAIGN: BMS BATTERY DIAGNOSTIC LOGIC IMPROVEMENT (PI2603) - This bulletin provides inform… |
| TSB_ELE422 | Service bulletin | May 28, 2026 | TECHNICAL SERVICE BULLETIN: INFOTAINMENT SYSTEM SOFTWARE UPDATE USING UPDATE. KIA. COM - This bulletin provides information and service proc… |
| TSB_ELE417 | Service bulletin | Apr 14, 2026 | TECHNICAL SERVICE BULLETIN: INFOTAINMENT SOFTWARE UPDATE PROCEDURE - This bulletin provides information on the process for downloading infot… |
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 SC335 a recall?
No. A service campaign 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 SC335 repair free?
A service campaign is usually paid by the manufacturer on the vehicles it names, within the terms and time limit the document sets; the dealer checks the VIN against the manufacturer’s list.
Which vehicles does SC335 cover?
The manufacturer filed it against 4 model years: 2024 Kia Niro, 2023 Kia Niro, 2024 Kia Sportage, 2023 Kia Sportage. 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 Sportage HEV (NQ5 HEV): built 15 Feb 2022 – 28 Oct 2023; 2023-2024MY Niro HEV (SG2 HEV): built 21 Jun 2022 – 6 Feb 2023 — the build date is on the certification label in the driver’s door jamb.