Oil Pressure Sensor: Description and Operation

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

OIL PRESSURE TELLTALE - The PCM sends a message to the I/P cluster over the Class II link to turn On the Oil Pressure telltale whenever the ignition is On and the EOP input at the PCM is low.