I'm having the same problem for months with a trane chiller mod# RTAA100CYF01AODOF SER#U96033894 we have tried everything we have changed the thermistors we have checked them they all reading right but still we keep getting this oil system fault obviously the compressor on circuit B is being flooded it is sweating all the way till the crankcase heater we replace the crankcase heater also and we keeping the differential of 4 degrees or close between the saturated evap ref temp and the compressor suction ref temp so our superheat is fine if anybody has any comments or suggestions it will be aprecciate