AUX Air Conditioner Error Codes Aux Air Conditioner Error Codes 1. HSF (Y) HV(Y) HS(Y) HSA(Y) HSB(Y) HVA(Y) digital display for the series ac error codes: Error source = PG motor response is abnormal Display Mode = E4 Performance precedence level = 1 Error source = Plastic Temp Sensor is abnormal. Display Mode = E1