Oil Pressure Sensor: Description and Operation

OIL PRESSURE SENSOR (DIESEL ENGINE) - ECM INPUT

Fig. 12 Engine Oil Pressure Sensor Location:

The 3-wire, solid-state oil pressure sensor is installed into the oil pressure galley on the engine block. It is located below and to the rear of the Engine Control Module (ECM) (Fig. 12).

Operation of the oil pressure sensor on the diesel engine is controlled by the Engine Control Module (ECM). The Powertrain Control Module (PCM) does not have any control over the sensor.

The oil pressure sensor uses three circuits. They are:
- A 5-volt power supply from the ECM
- A sensor ground through the ECM's sensor return
- A signal to the ECM relating to engine oil pressure

The oil pressure sensor has a 3-wire electrical function very much like the Manifold Absolute Pressure (MAP) sensor on the gasoline powered engine. Meaning different pressures relate to different output voltages.

A 5-volt supply is sent to the sensor from the ECM to power up the sensor. The sensor returns a voltage signal back to the ECM relating to engine oil pressure. This signal is then transferred (bussed) to the instrument panel on the CCD bus circuit to operate the oil pressure gauge and the check gauges lamp. Ground for the sensor is provided by the ECM through a low-noise sensor return.