The Error Codes Working Group, part of the CharIN Focus Group Charging Communication, is working to standardize error codes and diagnostics across electric vehicles (EVs), charging infrastructure, and backend systems. The initiative aims to improve reliability, simplify troubleshooting, and enhance interoperability throughout the EV charging ecosystem.
In a significant shift earlier this year, the working group moved the development process for the Unified Error Codes specification to a public GitHub repository. While the working group meetings remain open to CharIN members only, the new repository allows anyone from the broader e-mobility community to contribute to the specification development.
Through GitHub issues and pull requests, discussions, proposals, and changes can now be managed transparently and collaboratively. This open development model allows industry stakeholders to participate in shaping unified error code definitions independently from the subgroup meetings.
The initiative brings several important advantages for the EV ecosystem:
- Transparency: The specification development process is visible from the beginning, enabling stakeholders to follow discussions and contribute ideas.
- Collaboration: Industry participants can directly support the initiative by reporting issues or submitting proposals for new or improved error code definitions.
- Continuity: Error codes require ongoing refinement as technologies evolve. The GitHub-based workflow enables continuous development alongside the rapid growth of the EV charging industry.
The repository currently contains the draft specification for Unified Error Codes, representing a joint effort to harmonize diagnostics and error reporting across EVs, EVSE, and charging management systems.
Partnership with the Unified Error Codes Initiative
To further strengthen the effort, CharIN has established a strategic collaboration with the Unified Error Codes (UEC) Initiative, led by Karol Nowacki.
In a fragmented charging landscape, diagnostics remain one of the major barriers to reliable EV charging. The collaboration connects CharIN’s Error Codes Subgroup with the UEC open source framework to develop a protocol-agnostic unified error code list for EV charging.
Building on references such as DIN DKE SPEC 99003, MREC, and other industry initiatives, the project harmonizes overlapping definitions into a common data model.
CharIN hosts and co-manages the shared GitHub repository, with Patricia Laskowsky from General Motors and Karol Nowacki from UEC serving as designated project maintainers. This structure ensures transparent governance and open source publication of the specification.
Roadmap and Next Steps
The working group is currently developing the hardware error code definitions, which form the first layer of the unified specification. The next phase will focus on defining software-related error codes, with completion targeted for October 2026.
Further activities on the roadmap include:
- Defining a unified error code framework across hardware, communication, and software domains. Hardware coverage targeted for summer 2026, communication coverage for late summer 2026, and software definitions by October 2026.
- Aligning error code definitions with existing standards, including mapping failure criteria and references to relevant international standards.
- Enabling EVSE–back office communication via OCPP 2.0.1, including the definition of a common data structure and naming convention for hardware and communication error codes.
- Developing an EVSE–EV diagnostic communication pathway to exchange DTC and fault information, evaluating PLC-based TCP/IP communication and possible redundant channels.
These efforts will help ensure consistent diagnostics and improved interoperability across EVs, charging stations, and backend systems.
Get Involved
CharIN actively welcomes e-mobility experts and companies to contribute to the initiative. Broad industry participation is essential to ensure that future error codes reflect real-world use cases across OEMs, EVSE manufacturers, charging operators, and software providers.
Contributors are encouraged to share input on the error codes they plan to implement, associated telemetry requirements, and diagnostic workflows. Early collaboration will help align definitions across the ecosystem, enabling improved service diagnostics and a more reliable charging experience for EV drivers.
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