Oil Pressure Sensor: Description and Operation

The Engine Oil Pressure (EOP) switch is located towards the bottom of the engine block near cylinder # 6. The EOP switch is a normally closed switch that opens when engine oil pressure exceeds 3.6 ± (2.2) psi. The ECM supplies ignition voltage through a resistor to the EOP switch. With ignition On, engine Off, the ECM EOP switch input will be low (near 0 volts, switch closed). When the engine is started, end engine oil pressure exceeds 3.6 ± (2.2) psi, the switch opens and the ECM EOP switch input goes high (ignition voltage).