NHTSA Service Bulletin 11014223: 2022-2025 Mercedes-benz C 300
Official manufacturer communication context for 2022-2025 Mercedes-benz C 300, 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.
Complaint Red cooling system malfunction warning due to overheat. Low engine performance. Check engine light on. Fault codes may be stored: P21814B The cooling system has a malfunction. There is a fault due to overtemperature. P2B8500 The rpm of the coolant pump is too low. Cause Various Remedy Check for loose plug at electrical connectors of high temp coolant pump (M43/10 or M75/11) by gently pulling on connector housings. Create a TIPS case and submit to powertrain team inbox if a loose plug is found at the coolant pump. Include: -Initial quick test -Details on any damage found to engine or cooling system. Include photos if applicable. -Any other relevant details.
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 11014223?
Complaint Red cooling system malfunction warning due to overheat. Low engine performance. Check engine light on. Fault codes may be stored: P21814B The cooling system has a malfunction. There is a fault due to overtemperature. P2B8500 The rpm of the coolant pump is too low. Cause Various Remedy Check for loose plug at electrical connectors of high temp coolant pump (M43/10 or M75/11) by gently pulling on connector.
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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