What does it mean when it says 'Abnormal oil pressure, please turn off the engine'?

[LaMarley]

Abnormal oil pressure prompting engine shutdown is typically caused by an oil filter check valve issue. If the oil filter is ruled out, there's likely a check valve beneath the oil filter that needs replacement. Below is relevant information about oil pressure regulators: 1. Definition: The oil pressure regulator is essentially a diaphragm-controlled overflow valve. The diaphragm divides the regulator into an upper spring chamber and a lower fuel chamber. It controls the opening of the overflow valve to maintain pressure balance between the two chambers. 2. Working principle: When fuel chamber pressure exceeds the combined force of spring pressure and vacuum pressure, the diaphragm arches upward, opening the regulator valve. Some fuel then returns to the tank through the return port via the ball valve, reducing pressure. When pressure drops to the regulator's set control pressure, the ball valve closes to maintain proper pressure in the fuel line between the pump check valve and pressure regulator.