EGR Backpressure Transducer: Description and Operation

Differential Pressure Feedback EGR (DPFE) Sensor:

PURPOSE
The Differential Pressure Feedback (DPFE) Sensor outputs a voltage proportional to the pressure drop across the metering orifice and supplies it to the Powertrain Control Module (PCM) as EGR flow rate feedback.

OPERATION
The DPFE receives this exhaust pressure signal through two hoses referred to as the downstream pressure hose (REF SIGNAL) and upstream pressure hose (HI SIGNAL). The Hi and REF Signals are marked on the DPFE sensor. The DPFE monitors the differential pressure across a metering orifice located in the orifice tube assembly.






Aluminum Housing (.55 or 1.0 volt Null Output)






Plastic Housing (1.0 volt Null Output)


DPFE Sensor Types Available
There are two visually distinct DPFE sensors being manufactured. One is the original, aluminum-cast housing sensor found on most applications. The second is a new, plastic housing sensor designed to perform the same function.

Some applications will also have either sensor with a modified voltage output. Verify the sensor part number to identify the correct DPFE sensor for all applications.

CONSTRUCTION
The DPFE sensor is a ceramic capacitive type pressure transducer.