NHTSA Service Bulletin 11023588: 2021 Ram 2500
Official manufacturer communication context for 2021 Ram 2500, 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.
Flash: Amplifier (AMP) Diagnostic and System Updates **Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):** B143B-12 - ANC Microphone 1-Circuit Short To Battery. B143C-12 - ANC Microphone 2-Circuit Short To Battery. B143E-12 - ANC Microphone 3-Circuit Short To Battery. B143F-12 - ANC Microphone 4-Circuit Short To Battery. NOTE: The DTCs are wrongly set and do not affect Active Noise Cancellation (ANC) performance This bulletin involves updating the AMP with the latest available software.
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 11023588?
Flash: Amplifier (AMP) Diagnostic and System Updates **Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):** B143B-12 - ANC Microphone 1-Circuit Short To Battery. B143C-12 - ANC Microphone 2-Circuit Short To Battery. B143E-12 - ANC Microphone 3-Circuit Short To Battery. B143F-12 - ANC Microphone.
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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