TECHNICAL SERVICE BULLETIN: BMS DTC JUDGEMENT LOGIC IMPROVEMENT - This bulletin provides the procedure to update the software logic of the Battery Management System (BMS) on some 2019-2022MY Niro EV (DE EV) vehicles produced from December 5, 2018 through April 12, 2022. The BMS ECU monitors voltage deviation between battery cells, poor insulation, abnormal cell voltage changes after charging, abnormal current change during charging, over-voltage, temperature deviation or average cell deviation during driving is detected. These conditions can cause the BMU to set DTC P1AA600. The affected vehicles may exhibit a reduction in power and speed (limp home mode) and a MIL 'ON' with DTC P1AA600 stored. 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.
