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/Standard_Flyers/st10235po4-feb14_jtf-po401code_a.pdf
JUST THE FACTS StandardBrand com IntermotorImport com EVR VS63 DPFE Sensor VP8 Don t Get PO ed with PO401 Codes Ford P0401 Issues The Ford EGR Pressure Feedback system is known for persistent P0401 EGR low flow code issues Bear in mind low flow can be caused by several issues The most common issue is the failure of the EGR Pressure Feedback sensor commonly known as the DPFE sensor If the diaphragm in the sensor becomes weak or the sensor is contaminated with moisture it can fail to supply the computer with the correct reference voltage When this occurs the computer increases the vacuum supply to the EGR valve causing the vehicle to run poorly When the low flow signal is unable to be corrected by the computer s adjustment then the computer sets a P0401 code for EGR flow System Diagram The other parts that commonly get overlooked are the EGR Valve Regulator EVR which is cataloged as an EGR control solenoid the DPFE hoses and carbon build up inside the EGR system The EVR is responsible for supplying the proper vacuum to the EGR valve Any resistance in this control circuit or failure of the EVR can cause a P0401 code The original DPFE hoses are a special high temperature hose These hoses can crack or collapse internally over time due to intense thermal cycling that takes place within the EGR system To prevent a reoccurrence of the P0401 code Standard recommends inspecting and replacing if necessary the EVR and DPFE hoses when replacing the DPFE sensor To further guard against a P0401 code a de carbonization treatment of the EGR system should be performed ST10235PO4 FEB14
