NHTSA service bulletin

NHTSA Service Bulletin 10190705: 2021 Ram 1500

Official manufacturer communication context for 2021 Ram 1500, with affected products, buyer checks and links into Carchieve recall, problem and VIN research.

NHTSA service bulletin 10190705 summary graphic for 2021 Ram 1500
10190705NHTSA document ID
Manufacturer communicationcommunication type
1affected product rows
92/100quality score

Reviewed June 2026 from NHTSA manufacturer communication and service bulletin records. Carchieve is independent and not affiliated with any vehicle manufacturer or government agency.

Quick answer

Flash: Hybrid Control Processor (HCP) Updates This bulletin involves updating the HCP with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes (DTCs). P1A26-00 - BPCM Hybrid Battery State Of Charge Performance. P0A7E-00 - Hybrid/EV Battery Pack Over Temperature. U1003-00 - ESP Can C Bus Performance. P2534-00 - Ignition Switch Run/Start Position Circuit Low. P0506 - Idle Speed Performance Lower Than Expected. P0507 - Idle Speed Performance Higher Than Expected. One Trip DTC Changed to a Two Trip DTC.P0AC6-00 - Hybrid/Ev Battery Temperature Sensor 2 Circuit Performance. P0ACB-00 - Hybrid/Ev Battery Temperature Sensor 3 Circuit Performance. U0121-00 - Lost Communication With Anti-Lock Brake System (ABS) Control Module. U0140-00 - Lost Communication With Body Control Module. U1818-00 - Lost Communication With ECM/PCM On D-PT Can. U0100-00 - Lost Communication With ECM/PCM. U0102-00 - Lost Communication With Transfer Case Control Module / AWD. U1003-00 - ESP Can C Bus Performance. P0562 - Battery/System Voltage Low. P060C-00 - Internal Control Module Main Processor Performance. U0415-00 - Implausible Data Received From ABS. U1850-00 - Implausible Data Received From PCM on D-PT. Two Trip DTC Changed to a One Trip DTC.P0E52-00 - DC/DC Converter Current Sensor Circuit A Range/Performance. P0C39-00 - DC/DC Converter Temperature Sensor 1 Performance. P0C3E-00 - DC/DC Converter Temperature Sensor 2 Performance. P0E59-00 - DC/DC Converter Temperature Sensor C Circuit Range/Performance. P0E32-00 - DC/DC Converter Voltage Sensor 1 Performance. P0E37-00 - DC/DC Converter Voltage Sensor 2 Performance. P2C8D-00 - DC/DC Converter Temperature Sensor "D" Circuit Range/Performance. P2535-00 - Ignition Switch Run/Start Position Circuit High. P2534-00 - Ignition Switch Run/Start Position Circuit Low.

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

MakeModelModel yearsBuyer note

Buyer checklist

  1. Run the 17-character VIN and confirm the year, make, model, engine and equipment match the listing.
  2. Check recall campaign pages for safety actions that may require dealer repair.
  3. Compare this bulletin with common problem pages for the same model and component area.
  4. Ask the seller or dealer whether the bulletin procedure, update or inspection has already been completed.
  5. Use the used-car buying checklist and get an independent inspection.

Frequently asked questions

What is NHTSA service bulletin 10190705?

Flash: Hybrid Control Processor (HCP) Updates This bulletin involves updating the HCP with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes (DTCs). P1A26-00 - BPCM Hybrid Battery State Of Charge Performance. P0A7E-00 - Hybrid/EV Battery Pack Over.

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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