DeVille V8-4.6L VIN 9 (1995)
Oil Pressure Switch (For Fuel Pump): Description and Operation
FUEL PUMP SWITCH AND ENGINE OIL PRESSURE SENSOR
The fuel pump switch and engine oil pressure sensor is mounted in the oil filter adapter and consists of two sets of switch contacts that serve
separate purposes. One set is open with normal oil pressure and provides a signal to the Instrument Panel Cluster (IPC). The IPC assumes normal
oil pressure when the switch is open and is alerted to a low oil pressure condition when the switch closes. The IPC then alerts the driver with a
message on the Driver Information Center (DIC) and an audible warning.
The other set of switch contacts serves as a backup system to the PCM and fuel pump relay. The switch contacts close when oil pressure builds
above 28 kPa (4 psi). If the PCM and/or fuel pump relay has failed, the fuel pump switch and engine oil pressure sensor will close once pressure
reaches 28 kPa (during an extended crank) and will provide battery voltage to the fuel pump.
