Diagnostic Communication with Zero Emission Vehicles (ZEV) Using ISO 14229-5 (UDS on IP) and SAE J1979-3 (ZEV on UDS) 2024-01-1985
SAE J1979 and its “OBD Modes” served for the protection of our environment against harmful pollutants for decades, but due to regulatory adoption of Unified Diagnostic Services (UDS), SAE J1979 has now become a multiple part document series: SAE J1979 will be replaced by SAE J1979-2 for vehicles with combustion engines (ICEs) and by SAE J1979-3 for Zero Emission Vehicle (ZEV) propulsion systems. For ZEVs, emission-related failures will be replaced by ZEV propulsion-related failures.
Both SAE J1979-2 and -3 are variants of ISO 14229 (UDS) but limited to emission-related and ZEV propulsion-related failures, respectively, and associated diagnostic data. These new diagnostic communication protocols are required by California Air Resources Board (CARB) but do not support vehicle-manufacturer-specific diagnostic applications like calibration or flash programming. For performance reasons of the flash process, the deployment of UDS on Internet Protocol (UDSonIP) as it is standardized in ISO 14229-5 became state-of-the art.
This paper describes the basics of UDSonIP, Diagnostic communication over Internet Protocol (DoIP) and ZEVonUDS. It also covers how DoIP is used for diagnostic communication with the ZEV propulsion system to read the VIN. Finally, it provides a comparison between DoIP and Diagnostic communication over Controller Area Network (DoCAN), based on the analysis of a hex dump.
