Accessing Battery Management System (BMS) data in electric vehicles like the Hyundai Ioniq can provide valuable insights into battery health and performance. While the CAN bus in the Ioniq might appear quiet, it’s indeed possible to retrieve BMS information using OBD2 AT commands by sending specific query requests and awaiting the response.
Unlike some systems where CAN bus traffic is readily visible, the Ioniq seems to operate with a filtered or routed CAN setup, making direct sniffing ineffective via the internal diagnostic connector. However, this doesn’t prevent data retrieval. By using an OBD-II interface and sending the correct AT commands, you can successfully communicate with the BMS.
One proven method involves utilizing specific OBD query commands. The command format 7E4#022101, and its sequential counterparts such as 7E4#022102, 7E4#022103, 7E4#022104, and 7E4#022105, have been identified as effective for extracting BMS data from the Hyundai Ioniq. These commands, when executed through an OBD-II terminal, prompt the BMS to transmit valuable data concerning the battery system. Further research into the function of the initial “02” within these commands, preceding the core “2101” instruction, could yield a deeper understanding of the underlying communication protocol.
To effectively interpret the raw hexadecimal data obtained from these commands, resources like the JejuSoul OBD-PIDs for HKMC EVs GitHub repository are indispensable. This repository serves as a comprehensive guide, detailing Parameter IDs (PIDs) relevant to Hyundai and Kia EVs, including the Ioniq. It provides clear explanations of what each PID represents and the necessary conversion formulas to transform the raw HEX data into meaningful, human-readable values.
A critical point to remember is that the Hyundai Ioniq’s BMS, along with other electronic control units within the vehicle, will only respond to OBD2 queries when the car is in an active ‘ON’ state. Attempting to retrieve data when the vehicle is powered off will result in no response. Therefore, ensure the vehicle is properly powered on to establish communication and successfully access the BMS data.
By employing these OBD2 AT commands and leveraging resources like the JejuSoul GitHub repository for PID interpretation, you can gain valuable access to and understanding of your Hyundai Ioniq’s BMS data. This capability empowers you to perform in-depth diagnostics, monitor battery health, and potentially optimize the performance and longevity of your electric vehicle’s battery system.
