# Service bulletin SC352\_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.

- Type: Service bulletin
- NHTSA id: 11025769
- Published by NHTSA: 2025\-12\-01
- Manufacturer's number: SC352\_TSB
- Manufacturer's date: 2025\-11\-11
- Campaign id or software version: SC352
- NHTSA component: ELECTRICAL SYSTEM

## NHTSA's summary

VOLUNTARY SERVICE CAMPAIGN: HVAC SOFTWARE UPGRADE FOR PTC OPERATION LOGIC IMPROVEMENT \(SC352\) \- This bulletin provides information to upgrade the Heating, Ventilation, and Air Conditioning \(HVAC\) control software on certain 2025\-2026MY Carnival HEV \(KA4 HEV\) vehicles produced from May 16, 2024 through September 8, 2025, to prevent excessive discharging of the 12V battery by the Positive Temperature Coefficient \(PTC\) heater under certain operating conditions. When the engine is below operating temperature, the PTC heater is used to provide additional heat to the cabin. In very cold environments and under high electrical load, the PTC heater in the subject vehicles may discharge the 12V battery faster than it can charge. If the 12V battery becomes excessively discharged, the vehicle may enter Limp Home Mode with speed temporarily limited to a maximum of 31mph until the vehicle reaches normal operating temperature. There are no warning lamps or warning messages associated with this condition.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11025769-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11025769-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Electrical system

## Vehicles listed

- 2025 to 2026 KIA CARNIVAL HYBRID

## Recalls for the same vehicles and component

- [26V046000](/recalls/nhtsa/26V046000.md), 2026-01-26: ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL

## Other bulletins for the same vehicles and component

- [OTA\_ELE413\_NOTES\_R2](/bulletins/11033980.md), 2026-06-18, Over\-the\-air update: ELECTRICAL SYSTEM. RELEASE NOTES: OVER\-THE\-AIR: SOFTWARE UPDATE FOR DATA CONNECTIVITY \(ELE413 Revision 2\) \- This Over\-the\-Air \(OTA\) software update is designed to update the Data Connectivity Unit \(DCU\) logic of certain 2025 \- 2026MY Carnival, EV9, K5 and Sorento vehicles. This update is designed to improve the vehicle’s network communication performance.
- [TSB\_ELE422](/bulletins/11033217.md), 2026-06-03, Service bulletin: ELECTRICAL SYSTEM. TECHNICAL SERVICE BULLETIN: INFOTAINMENT SYSTEM SOFTWARE UPDATE USING UPDATE.KIA.COM \- This bulletin provides information and service procedures for updating the infotainment systems on applicable Kia vehicles using the Kia Navigation Updater available at update.kia.com. The software update may improve system performance, enhance existing features, and apply the latest operating software for supported vehicles \(2021\-2026MY All Models\).
- [OTA\_ELE413\_NOTES\_R1](/bulletins/11031940.md), 2026-05-01, Over\-the\-air update: ELECTRICAL SYSTEM. RELEASE NOTES: OVER\-THE\-AIR: SOFTWARE UPDATE FOR DATA CONNECTIVITY \(ELE413 Revision 1\) \- This Over\-the\-Air \(OTA\) software update is designed to update the Data Connectivity Unit \(DCU\) logic of certain 2025 \- 2026MY Carnival, 2025 \- 2026MY K5 and 2025 \- 2026MY Sorento vehicles. This update is designed to improve the vehicle’s network communication performance.
- [TSB\_ELE417](/bulletins/11031906.md), 2026-05-01, Service bulletin: ELECTRICAL SYSTEM. TECHNICAL SERVICE BULLETIN: INFOTAINMENT SOFTWARE UPDATE PROCEDURE \- This bulletin provides information on the process for downloading infotainment software updates and preparing USB for installation on applicable Kia vehicles. The software downloads and USB preparation process is similar across all supported platforms; however, in‑vehicle installation procedures vary by head unit type.
- [TSB\_ELE413](/bulletins/11030344.md), 2026-03-31, Service bulletin: ELECTRICAL SYSTEM. TECHNICAL SERVICE BULLETIN: DCU COMMUNICATION LOGIC IMPROVEMENT \- This bulletin provides the procedure to upgrade the Data Connectivity Unit \(DCU\) system software on some 2025–2026MY vehicles listed in the table below. Kia has identified that Connected Car Services \(CCS\) functionality may intermittently fail due to temporary DCU communication issues. This condition can impact convenience and connectivity features by causing the Remote Start and Remote Climate functions to become inoperative, prevent vehicle status updates in the Kia Access app, and interrupt connected navigation routing services.
- [PS807](/bulletins/11029974.md), 2026-03-12, Service bulletin: ELECTRICAL SYSTEM. PITSTOP: TECHNICAL OPERATIONS: CCU FUSE OPEN AFTER WIRING HARNESS REPLACEMENT \- This Pitstop provides information regarding a condition on 2022\-2026MY Carnival \(KA4 and KA4 HEV\) vehicles in which the CCU 10A fuse may open and multiple warning lights may illuminate after replacement of the front dash wiring harness.
- [PS798](/bulletins/11027676.md), 2026-01-16, Other: ELECTRICAL SYSTEM. PITSTOP: TECHNICAL OPERATIONS: CCRC WITH DTC B281600 \(PS798\) \- This Pitstop provides information regarding DTC B281600 stored on some 2025 \- 2026MY Carnival \(KA4, KA4 HEV\) vehicles equipped with Connected Car Rear Cockpit ‘ccRC’ rear seat entertainment screens. When performing a diagnostic scan using the Kia Diagnostic System ‘KDS’, DTC B281600 can become stored but does not cause any concerns with functionality of the ccRC system. DTC B281600 does not trigger any warning lights and does not indicate any hardware malfunction within the ccRC system and does not perform any meaningful diagnostic function. No further diagnosis, Techline case and/or repairs are necessary for DTC B281600 unless there is an active customer complaint of the ccRC system. This issue is expected to be resolved through a future ccRC Over\-The\-Air ‘OTA’ update.
- [PSD\_REMINDER\_103](/bulletins/11026826.md), 2025-12-24, Other: STRUCTURE:BODY; ELECTRICAL SYSTEM. IMPORTANT REMINDER: CARNIVAL POWER SLIDING DOOR FEATURE: OWNER NOTIFICATION \(KA4PSD2 FLIGHT 103\) \- This document is the owner notification advising Kia's ongoing commitment to providing vehicle owners with a superior ownership experience. We would like to remind vehicle owners about the proper use of the power sliding door and its automatic stop and reversal feature in the Kia Carnival. The power sliding door feature is designed to enhance accessibility and ease of use, but it’s important to understand its functions and limitations to ensure safe and reliable operation.
- [SC352\_OWNR](/bulletins/11025940.md), 2025-12-02, Service campaign: ELECTRICAL SYSTEM. VOLUNTARY SERVICE CAMPAIGN: OWNER NOTIFICATION \(SC352\) \- This document is the owner notification advising that Kia is conducting a Voluntary Service Campaign on certain 2025\-2026 MY Carnival Hybrid \(HEV\) vehicles to update the Heating, Ventilation, and Air Conditioning \(HVAC\) control software to prevent excessive discharging of the 12V battery by the Positive Temperature Coefficient \(PTC\) heater under certain operating conditions.
- [SC352\_DP](/bulletins/11025856.md), 2025-12-01, Service campaign: ELECTRICAL SYSTEM. VOLUNTARY SERVICE CAMPAIGN: DEALER PRINCIPAL MEMO \(SC352\) \- This document is the announcement to the dealer principals advising that Kia is conducting a Voluntary Service Campaign on certain 2025\-2026 MY Carnival Hybrid \(HEV\) vehicles manufactured from May 16, 2024 through September 8, 2025 to update the Heating, Ventilation, and Air Conditioning \(HVAC\) control software to prevent excessive discharging of the 12V battery by the Positive Temperature Coefficient \(PTC\) heater under certain operating conditions.

JSON: [/v1/bulletins/11025769](/v1/bulletins/11025769)

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