23 Voltage supply 3 - Coolant control valve and reverting valve (UB3) electrical - Short circuit to Ground UB3 - P20A2 Vent valve (Reductant Purge Control Valve) - Short circuit low
Voltage supply 3 -Coolant control valve and reverting valve (UB3) electrical - Open circuit to B3 - P20A0 Vent valve (Reductant Purge Control Valve) -open circuit
Hissing noise at expansion valve, Loss of refrigerant.Restriction in refrigerant system.Check receiver-dryer for uniformity of temperature.