Hi All,
I'm working through my EX fixing all the PO issues, and have come upon a little mystery. I have the aluminum DPFE, but someone cut the plug off. So, I bought a new plug, but all three wires on it are white. I have a new DPFE on order.
The cut wires from the harness are Br/Wh, Br/Gr, and Gry/R.
I know from diagrams that I've found, that the Br/Wh is the VREF, the Br/Gr is DPFE in signal, and the Gry/R might be ground. But, what I don't know, is to which position on the plug and DPFE each wire goes to, i.e., which wire goes to the middle position of the plug, which goes to the top, in relation to the Up arrow on the DPFE, etc..

Anyone have a diagram, or can take a picture of it for me?

Thanks!

 

The diagrams I have don't show it. Here's a article I found that describes the position of the wires. They say the top is the signal wire, the middle wire is the vref, so that leaves the bottom as the ground. My diagrams did show

brown/white is vref

brown/lightgreen is signal

grey/red is the ground

Here's the link. Is this your engine? 2002 Explorer Egr Problem | Extreme Check Engine Light Codes

 

The diagrams I have don't show it. Here's a article I found that describes the position of the wires. They say the top is the signal wire, the middle wire is the vref, so that leaves the bottom as the ground. My diagrams did show

brown/white is vref

brown/lightgreen is signal

grey/red is the ground

Here's the link. Is this your engine? 2002 Explorer Egr Problem | Extreme Check Engine Light Codes

 

You can almost make out the colors in this picture.

 

Don't know if this is the correct sensor. It has one pipe not two. And the order of the wires is different.

 

And that is exactly what I was finding. Amongst all the diagrams, descriptions, and images I found, the order of the wires were not consistent. You would think that the order would be the same, but not necessarily the wiring colors.

Initially, I found a diagram with the wire descriptions, and figured I had it sorted out, then I found this image, which contradicted it.

Oh, and the DPFE in this picture is the same as mine. The second tube is hidden behind the front one.

 

That one article says the sensor is just a variable resistor. If that's true, it will be just like a volume control or a potientiometer. If you have a voltmeter with a ohms function, you may be able to figure it out.

It will measure out to be a plain resistance from vref to ground, and the signal will be the "wiper". So the resistance from the vref to the signal + the resistance of the ground to the signal is going to equal the total resistance from vref to ground.

You probably can get a small (clean) hose and hook it to the sensor and put a little pressure on it and make the resistance change.

So I will give an example, I don't really know the real resistance. But let's say the total resistance of the unit is 5K or 5000 ohms. You should get around 5K from vref to ground. Probably just sitting there you are going to get something like 0-100 ohms from the signal to vref, and you will get 4900-5000 from the signal to ground. It may be reverse though.

If you blow on the tube slightly, you should see the readings change, but always adding up to around 5000 (or whatever the total resistance of the unit is).

The next problem you will have figure out with some research, or maybe you already know; With the engine off is the signal voltage supposed to be low or high? That will determine which end of the resistor gets the vref and which end gets the ground wire. If the signal is low voltage with no pressure, then the ground will hook to the terminal that you get a very low reading on to the signal wire, and the vref will go to the terminal that has the high resistance to the signal wire.

Does this make sense? I know it's confusing. Here's a picture that may help.