As the automotive industry shifts toward software-defined vehicles, managing ECU (Electronic Control Unit) software updates has become increasingly complex. At the core of ECU software updates is the UDS protocol (Unified Diagnostic Services)—a standardized yet detailed communication framework that ensures safe and reliable updates. Traditionally, the UDS update process is hardcoded into OTA process, making it difficult to scale and maintain across diverse ECU types.
Redstone OTA introduces a new approach: using XML to define and execute UDS update workflows, enabling automakers to achieve more flexible, efficient, and maintainable software updates.
The Role of UDS in ECU Updates—and Its Challenges
UDS (Unified Diagnostic Services), standardized under ISO-14229, is the primary protocol used for flashing vehicle ECUs. It governs a series of message exchanges required to prepare, transfer, and validate updated software within each ECU.
Common Challenges Automakers Face:
- Diverse UDS Requirements from Different ECU Suppliers
Each supplier may implement slight variations in the UDS update sequence. Managing these differences traditionally requires modifying and recompiling OTA source code for every variation—an error-prone and time-consuming process. - Inflexibility of Hardcoded Sequences
With traditional systems, update steps are embedded directly in the software. Any change in message order, timing, or content requires code updates and full regression testing, slowing down deployment. - High Maintenance and Error Risk
When multiple ECUs use unique update sequences, maintaining those workflows in code increases complexity and the risk of failure during an update.
Redstone OTA: Using XML to Describe UDS Update Workflows
Redstone OTA replaces fixed, embedded UDS sequences with dynamic XML configuration files. These files describe the steps the OTA program must perform during each ECU software update.
How It Works:
- The automaker or supplier prepares an XML file that outlines the complete sequence of UDS operations: session control, security access, memory erase, data transfer, and completion.
- This XML file is delivered alongside the upgrade package to the OTA client.
- The OTA client reads the XML, stores the sequence in memory, and performs each operation as defined.
This XML-based method enables Redstone OTA to handle any ECU’s specific requirements without changing the OTA software itself.
Why XML Makes UDS-based ECU Updates Smarter
By externalizing UDS update workflows into XML files, Redstone OTA provides several key advantages:
1. No Software Rebuilds Needed for New ECUs
If an ECU requires a different update sequence, the only change needed is in the XML file. No OTA software modifications or recompilation are required.
2. Faster Integration with New ECU Suppliers
Automakers can onboard ECUs from new suppliers quickly by defining their UDS workflow in XML—without modifying existing OTA infrastructure.
3. Improved Maintainability
Separating the UDS sequence from the OTA codebase reduces long-term technical debt and simplifies maintenance, validation, and updates.
4. Real-Time Execution with High Reliability
Redstone OTA loads the XML file into memory and executes each defined step in sequence—sending messages, processing responses, applying delays, and completing the update smoothly.
XML + UDS = Configurable, Scalable ECU Updates
Combining the standardized structure of UDS with the flexibility of XML enables Redstone OTA to deliver:
- Seamless support for multi-vendor ECUs
- Update workflows tailored to each ECU
- Reduced engineering workload
- Accelerated time-to-market for new models
This approach ensures that each update process is fully customized and reliably executed—without compromising on consistency or safety.
Conclusion: Redstone OTA Transforms ECU Updates with XML-Defined UDS Sequences
The traditional way of embedding UDS update steps in OTA code no longer fits the fast-moving, multi-supplier reality of today’s automotive industry. Redstone OTA offers a better solution: define UDS update sequences using XML files that travel with the update package.
This model brings flexibility, reduces development effort, and improves update success rates—helping automakers future-proof their vehicle software infrastructure.
