UNECE R156

UN Regulation No. 156 (Software Update and Software Update Management System) governs how software on type-approved vehicles is changed after approval. Like its counterpart UN R155, it operates at two levels. At the organisational level, the manufacturer must run a certified Software Update Management System (SUMS): documented processes for planning updates, assessing whether a change affects any type-approved system, protecting update packages, informing vehicle users, and keeping auditable records; the SUMS Certificate of Compliance is valid for up to three years. At the vehicle level, the type must be shown to receive updates safely and securely — packages protected against manipulation, integrity and authenticity verified before installation, a safe state if an update fails or is interrupted, and sufficient power to complete the process. R156 also introduces the RXSWIN, the software identification number that ties the software configuration relevant to each regulation to the approval it belongs to; when an update changes regulated software, the RXSWIN must change with it and remain traceable. The regulation applies to vehicle manufacturers seeking type approval in adopting 1958-Agreement markets — in the European Union on the same schedule as UN R155 under Regulation (EU) 2019/2144: new vehicle types from 6 July 2022, all new vehicles from 7 July 2024. It covers every update path, workshop reflash and over-the-air alike, though OTA capability is what makes SUMS discipline hardest to sustain. ISO 24089, the road-vehicle software-update engineering standard, is the engineering companion commonly used to implement it, and India's AIS 190 is the domestic derivation.