This bulletin provides information to update the software logic of the Battery Management System (BMS) on some 2022-2023MY EV6 (CV) vehicles produced from November 17, 2021 through February 3, 2023 which have a stored DTC P1AA600. The BMS ECU monitors voltage deviation; if over-voltage deviation between battery cells, poor insulation, abnormal cell voltage changes after charging, abnormal current change during charging, over-voltage, low voltage battery temperature deviation or average cell deviation during driving is detected, the BMU sets DTC P1AA600. This BMS DTC logic improvement will expand DTC P1AA600 into multiple DTCs to aid in proper diagnosis, which reduces the required time and steps outlined in the ‘DTC Inspection’ on KGIS to determine the fault using ‘freeze frame’ data (refer to table below).
** This update is also included in ELE291; it does not require a separate update. They both update the BMS software version to 5500 or 5508.