Theory Of Operation
WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) provides a 5-Volt supply to the Engine Oil Pressure (EOP) Sensor on the sensor supply circuit. The PCM also provides a ground on the sensor return circuit. The Engine Oil Pressure Sensor signal can be a pull up (5.0 volts) or pull down (0.0 volts) resistor depending on the PCM internal hardware for the signal circuit. This can vary between vehicles and model years.