V150 buzzer on after start

[Will_Heyer]

I have a V150 hp Merc that when you turn the key it does the system check beep , then beep/beep and stops. Then When you start the engine alarm starts to beep/beep. It is not the thermal switch as this would be a continuous beep. The oil tank is filling as it should. I am thinking it is the oil pump module. How can I test this? Its $240 so I would like to be sure.

Any help would be helpful.