Pressure Feedback Exhaust Sensor: 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.

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.