[A930Rocket]

It only has one wire.

From a google search:

Here's a more detailed breakdown:
Function:
The sensor's main job is to detect low oil pressure, not to provide a precise reading of the pressure.

Mechanism:
It typically uses a spring-loaded diaphragm and a switch. When oil pressure is sufficient, it pushes the diaphragm against the switch, keeping it open and the warning light off.

Low Pressure Scenario:
If the oil pressure drops below a certain threshold (the "switch point"), the diaphragm relaxes, allowing the switch to close and the warning light to illuminate.

From the last paragraph, it would seem that the wire makes a connection to ground, sends a signal to the ECM for low oil pressure warning, and turns off the engine