BMW Repair: Fault code P1624, 2000 bmw 323ci, coolant temperature switch

Question
I have a code that keeps coming up which is P1624. It just says it is AUX inputs AUX outputs manufacture control. Would you happen to know what this code is and where the part might be. Was told that it might be the coolant thermostat. Have a 2000 BMW 323CI with a M52 engine.

Answer
Code P1624:M52 coolant temperature below thermostat regulating temperature.I would check the temperature of the coolant and also with a scan tool check the actual reading given by the coolant temperature switch.It could be the thermostat or a coolant sensor.Look also for any broken/corroded wires to the sensors as well.