TECHNICAL SERVICE BULLETIN: MQ4 P/HEV GAMMA 1.6L T-GDI ECM & HCULDC LOGIC IMPROVEMENT FOR OIL DILUTION: This bulletin provides the procedure to update the software logic of the 'Engine' and Hybrid Control Unit Low DC-DC Converter 'HCULDC' systems on certain 2021-2023MY Sorento HEV, PHEV (MQ4 P/HEV) w/ Gamma 1.6L T-GDI vehicles produced from July 1, 2021 through November 3, 2022. The affected vehicles may exhibit a MIL 'ON' with DTCs stored (P144100, P1A7795, P00B700, P211800, P040100, P023600, P029900, P2B6000) due to the engine oil becoming diluted with fuel and/or moisture caused by repeated short drive trips, in low outdoor temperature (32 degree F-) environments.