How to Test the DPFE Sensor

The Differential Pressure Feedback Exhaust Sensor, or DPFE sensor, is part of the vehicle's exhaust gas recirculation (EGR) system. The sensor monitors and measures the pressure with the EGR valve. This prevents the valve from malfunctioning and allowing too much exhaust into the intake manifold at one time. If a vehicle's running poorly or having poor gas mileage, the DPFE sensor may be to blame.

1. Open the hood of the vehicle

Open the hood of the vehicle. Locate the DPFE sensor, which is near the EGR valve, behind the upper intake manifold, between the firewall and engine. The sensor is a small square with two vacuum hoses on the bottom and a wire harness coming out from the side. The location will vary slightly from make and model. Check your repair manual for exact location and a detailed diagram.

2. Disconnect the two vacuum hoses from the sensor

Disconnect the two vacuum hoses from the sensor by giving them a firm tug.

3. Turn the ignition key to the “On” position

Turn the ignition key to the “On” position. Do not turn the engine off. You want the sensors to run and PCM to turn on, but the engine to remain off.

4. Connect the negative (black) multimeter lead to a ground point

Connect the negative (black) multimeter lead to a ground point, such as the negative battery terminal. Clip the positive (red) lead to the DPFE sensor signal wire. The sensor has three wires; the signal wire is the first wire on the left of the unit.

5. Allow the multimeter to register the voltage

Allow the multimeter to register the voltage. Ford DPFE sensors should read between .45 and .55 volts. All other makes should read between .8 and 1.0 volts. If the sensor is not within the appropriate range, the sensor is faulty and should be replaced.

Video: How to diagnose a Faulty Differential Pressure Feedback (DPFE) Sensor

Helpful comments on this video:

• Very Helpful video. I changed mine out on my 2004 Expedition and because I broke one of the stems on accident, and it gave me an oxygen sensor code for Bank 1, Sensor 1. I change the sensor and STILL have the check engine light on. I disconnected the battery to eliminate the code, but it came on again. I check it with the diagnostic reader from AutoZone and these codes came up (P2195, P0135, P0401 and P0402). I'm at wits end. I was going to go to a mechanic to erase the codes first and see if that will shut the light off. Any other advise? Thank you!
• All I had to do is remove the hose connected to the DPFE mine was dry rotted. I added a new transmission cooler hose with clamps and the code for P1405 hasn't shown back up for me.