Def Pressure Sensor

The DEF pressure control system uses the measured DEF pressure in a feedback control loop to achieve the desired DEF pressure. The DEF injection algorithm uses actual DEF pressure in its computation of DEF injector pulse width.

The DEF sensor is a gauge sensor. Its atmospheric reference hole is near the electrical connector. The DEF pressure sensor has a nominal range of 0 to 0.8 MPa (0 to 8 bar, 0 to 116 psi). This pressure range is above the maximum intended operating pressure of 0.5 MPa. The sensor voltage saturates at slightly above 0.5 and slightly below 4.5 volts.

DEF pressure is often a vacuum when the system purges after running. Vacuums cannot be measured by the DEF pressure gauge sensor as voltages will not be lower than 0.5 Volts.