TECHNICAL SERVICE BULLETIN: SERVICE ACTION: BMS/OPU/MCU LOGIC IMPROVEMENT (SA411) - This bulletin provides the procedure to improve the logic of the Battery Management System (BMS), Oil Pump Control Unit (OPU) and Motor Control Unit (MCU) on some 2017-2019MY Optima (JF P/HEV) vehicles, produced from August 25, 2016 through September 13, 2018 (refer to page 8) in order to improve the BMS diagnosis logic, OPU judgment logic for DTC P1B77 (High Voltage Battery Pre-Charging fault) and MCU communication logic.
