NHTSA Service Bulletin 11025769: 2025, 2026 Kia Carnival Hybrid
Official manufacturer communication context for 2025, 2026 Kia Carnival Hybrid, with affected products, buyer checks and links into Carchieve recall, problem and VIN research.
Reviewed June 2026 from NHTSA manufacturer communication and service bulletin records. Carchieve is independent and not affiliated with any vehicle manufacturer or government agency.
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.
What this bulletin may mean before buying
Treat this as service research, not a verdict on one car. Before you buy, compare this communication with official recall campaigns, model-level owner complaint patterns, and the exact vehicle’s VIN-decoded specifications. A bulletin can help you ask a seller or dealer sharper questions about software updates, known repairs, warranty extensions and service history.
Affected products listed in this communication
Buyer checklist
- Run the 17-character VIN and confirm the year, make, model, engine and equipment match the listing.
- Check recall campaign pages for safety actions that may require dealer repair.
- Compare this bulletin with common problem pages for the same model and component area.
- Ask the seller or dealer whether the bulletin procedure, update or inspection has already been completed.
- Use the used-car buying checklist and get an independent inspection.
Frequently asked questions
What is NHTSA service bulletin 11025769?
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.
Is a service bulletin the same as a recall?
No. A recall is a safety campaign with a required remedy for affected VINs. A service bulletin or manufacturer communication usually describes diagnostic, repair, software, warranty or service information.
How should a used-car buyer use this bulletin?
Use it as a research signal. Compare it with recalls, owner complaints, service records, a VIN report and an independent inspection before buying.
Check the exact VIN before you buy
Model-level pages show public safety patterns. A full VIN report helps confirm the exact vehicle, decoded specs, recall applicability and buyer checks.
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