Questions and Answers

Ford F-150 DPFE-EGR System Q. I have a 2001 Ford F-150 truck. V-6, fuel injected and the Check Engine Light came on. With the OBD-II tester we found P0401 and changed the EGRSV, the EGR valve and we are trying to find out what is next. The DPFE came back with a P1401 and we don't know what to do? We also, after changing the EGRSV, could not get vacuum to the EGR valve? What is the problem as Ford has been no help.

A. There are many things that can cause this code to set. First is to make sure all the vacuum lines are clear with no cracks and that they are on the correct fittings.

The Powertrain Control Module (PCM) controls the EGR vacuum regulator solenoid. The EGR vacuum regulator solenoid controls the vacuum to the EGR valve. When the EGR valve opens, exhaust gas flows to the intake manifold.

The differential pressure feedback EGR sensor measures the flow through the EGR valve to exhaust manifold tube and sends a signal to the PCM. A metering orifice in the EGR valve to exhaust manifold tube restricts the flow rate when the EGR valve is open.

This system is difficult to test at idle without a scan tool. The EGR system is, basically, inert at idle. What you can do is unplug the EGR Vacuum Regulator (EGR-VR) solenoid and apply power and ground. With power and ground applied, you should hear it open and be able to blow through it. With the EGR-VR closed, you should not be able to blow through it.

Power for the EGR-VR comes in through the red/yellow wire and out the brown/pink wire. the brown/pink wire goes to the PCM that makes the ground for the solenoid. So there should be power all the way to pin 47 of the PCM. Checking for power there will tell you if the EGR-VR wiring is good or not.

If you have power through the system, you probably have a bad PCM or Pressure Feedback Exhaust Sensor.