Oil Pressure Switch

The oil pressure switch is located in the engine block near the oil filter cartridge housing. The switch is closed with low engine oil pressure. The switch will be closed with engine not running. When the switch is closed the input at the PCM will be low (zero volts). The PCM sends a class II message to the I/P cluster to turn On the low oil pressure telltale. The switch opens with engine oil pressure. When the switch opens the PCM input will be high (ignition voltage). The PCM will command the low oil pressure telltale Off.