The Differential Pressure Feedback EGR sensor also referred to as (DPFE) 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 EGR sensor receives this signal through 2 hoses referred to as the downstream pressure hose (REF SIGNAL) and upstream pressure hose (HI SIGNAL). The HI and REF hose connections are marked on the 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 PCM as EGR flow rate feedback.
Removal & Installation
- Disconnect the Differential Pressure Feedback EGR (DPFE) sensor electrical connector and detach the wiring harness retainer.
- Carefully detach the DPFE sensor from the EGR valve tube
- To install, reverse the removal procedure.
Disconnect the DPFE sensor harness connector. With the ignition on and engine off, measure the voltage between VREF and SIGRTN terminals of the DPFE harness connector. If the voltage is 4 -5.5V, the power circuits to the sensor are okay.
NOTETypical sensor voltage with no EGR flow is between 0.25 volt and 1.3 volts. A higher voltage at idle may be due to a non-seating or heavily carboned EGR valve pintle. DPFEGR PID voltage must increase as the valve opens and decrease as the valve closes. A slow return voltage is an indication of a binding or slow closing EGR valve.