How To Test The Ford EGR Valve EGR Vacuum Solenoid, DPFE Sensor How To Test The Ford EGR Valve EGR Vacuum Solenoid, DPFE Sensor How To Test The Ford EGR Valve EGR Vacuum Solenoid, DPFE Sensor

Testing the EGR system on your Ford, Mercury, or Lincoln car or truck is a pretty easy affair. You don't need expensive testing equipment to do it and more importantly, with this article you'll be able to find out exactly what part (of the entire system) is BAD and needs to be replaced and in the process saving time and money.

You'll find step by step instructions on how to test:

  1. EGR Valve
  2. DPFE Sensor
    1. (Delta Pressure Feedback Egr)
  3. EGR Valve Vacuum Regulator Solenoid
  4. Power Circuits

This ‘How To Test’ article covers three different types of Ford EGR DPFE Sensors and below you'll find important info that'll help you to successfully troubleshoot/diagnose the EGR valve code that is lighting up your check engine light. Once you start testing, I recommend you start from TEST 1 and go from there.

Puedes encontrar este tutorial en Español aquí: Cómo Probar la Válvula EGR, el Sensor DPFE, y el Solenoide de Vacío de Ford (at:

Common Symptoms Of A BAD EGR Valve

The following are the most common symptoms that a Ford (or Mercury or Lincoln) car or truck will usually experience when there's a fault in the EGR System:

  1. Car or truck runs fine, but the check engine light (CEL) is on with an EGR Valve Fault Code:
    1. P0401 EGR System Flow Insufficient.
    2. P01406 EGR Valve Pintle Position.
  2. Rough Idle.
  3. Really BAD gas mileage.
  4. Lack of power as you accelerate the vehicle down the road.
  5. Car (or truck or mini-van) seems to run ok above 30 miles and hour but once you come to an idle, the engine barely stays running and/or idles rough. Once you take off again, it runs OK.

What Tools Do I Need?

Below is a list of must have tools that you'll need to successfully use the testing information in this article to solve the EGR valve system malfunction on your Ford, Mercury, or Lincoln car or truck.

  1. A multimeter (don't have a digital multimeter? Need to buy one? Click here to see my recommendations: Buying A Digital Multimeter For Automotive Diagnostic Testing).
  2. Vacuum pump.
  3. Vacuum gauge.
  4. About two feet of vacuum hose.
  5. A repair manual.
    1. For whatever remove and replace info you'll need that isn't covered by this article.
  6. A wire-piercing probe
    1. This tool, which you can attach to your multimeter, is a time-saver. Most of the tests that you're about to perform have to be done with the connector connected to its component and this tool will come in very handy! If you want to see what one looks like, click here: Wire Piercing Probe

Ford EGR Valve DPFE Circuit Descriptions

Ford EGR Valve DPFE Circuit Descriptions Ford EGR Valve DPFE Circuit Descriptions Ford EGR Valve DPFE Circuit Descriptions

As already mentioned, this article covers three different styles DPFE sensors. Two are bolted onto the engine (one is plastic and the other is metal), and the other is suspended in place just by the two hoses that are attached to it. They all function in the exact same manner. The following circuit descriptions apply to all three DPFE sensors in the image viewer.

  1. Circuit labeled 1:
    1. DPFE Flow Signal
  2. Circuit labeled 2:
    1. Sensor Ground.
  3. Circuit labeled 3:
    1. 5 Volt Reference Voltage.

To make it easy for you to test the particular DPFE sensor on your Ford (or Mercury or Lincoln) car or truck, I have included images of all three types of DPFE sensors with the specific circuit (you need to test) highlighted.

Also, the color of the wires of the DPFE Sensor or EGR Vacuum Regulator Solenoid, on your Ford or Lincoln or Mercury vehicle, will not match the ones in the photos in the image viewer, this is no cause for concern. The circuit descriptions are the same no matter what the individual color of the wires on your Ford (Lincoln, Mercury) car or truck.