EGR Backpressure Transducer: Description and Operation

CONSTRUCTION and OPERATION
The Differential Pressure Feedback EGR (DPFE) sensor is a ceramic, capacitive-type pressure transducer that monitors the differential pressure across a metering orifice located in the orifice tube assembly. The Differential Pressure Feedback sensor receives this 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 aluminum Differential Pressure Feedback EGR sensor housing for identification (note that the HI signal uses a larger diameter hose). The Differential Pressure Feedback EGR 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.

SPECIAL NOTE
There are two visually distinct Differential Pressure Feedback EGR 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 Differential Pressure Feedback EGR sensor for all applications.