Voltage specs at DPFE on 2002 3.8

Hi

I'm getting zero vacuum at my EGR and I'm trying to figure out if it's the DPFE sensor (apparently very common) or the Electronic Vacuum Regulator. Could someone tell me what the voltage should be?

Thanks

canflyboy

By the way - I checked the voltage on the brown/green wire and it's 3.14V and the other wire is 5V.

I think the DPFE voltage is around 1V. I'm looking for verification.

Thanks

Canflyboy

The voltage at idle doesn't really matter, what maters is that the voltage varies as the flow through the DPFE tube changes. The DPFE measures the differential pressure drop across an orifice in the tube and that signal is used to determine the flow of exhaust gas recirculating back into the engine. The DPFE voltage should be steady on both leads at idle and vary as it measures a change in pressure. When the van is running at higher RPM and the engine is warmed up the computer will tell the solenoid to apply vacuum to the EGR valve to open up the right amount to mix just enough exhaust back into the engine. The feedback to the computer to tell it is it got it right is the DPFE voltage.

Easy way to tell if the DPFE is working correctly is to force the EGR valve to open while the van is idling while you measure the voltage output on the leads. As you move the EGR valve more or less open, the voltage should change. If it doesn't then the DPFE is bad or you are not measuring it correctly (hopefully that is not the issue). I stuck one lead to ground and one to the lead (check both during the test because I can't remember which one varies or if both do). The way I moved the EGR valve was I took the vacuum hose off the solenoid connection (the one to to the EGR valve), then I took the vacuum line off the surge box for the heater controls and with the van idling, manually put the two lines together. If the EGR valve is working, the van should stall due to too much exhaust and not enough oxygen for combustion. The voltage on the DPFE should also vary as you do this. If it doesn't vary and the van does stall, then change the DPFE.

By the way, if you didn't know(on a 2001), the solenoid is in the middle behind the engine and the vacuum suge box is on the passenger side under the winsheild wiper cowel (black box with nothing else attached to it).

Ford wanted abotu $140 CAD for a new one and Lordco charges anywhere from $40 to $90 CAD depending on your level of discount, for the after market one, which I bought for myself and a friends van and have had no issues.

To my knowledge there should be no vacuum to the EGR valve at idle. It only gets vacuum when the EGR needs to function.

I was asking the same question just a few days ago.

Thanks for all the useful information Andrew1941. I had a 1401 code and found that it typically would mean that the DPFE has gone bad. I replaced the DPFE and as of yet, the code hasn't come back and when revving the engine, I get vacuum on the EGR tube. Before I replaced the DPFE, I couldn't get any vacuum.

Now my next problem. Stumbling when accelerating. I had a #3 ignition fault and managed to find a new plug wire and replaced the #3 ignition wire and as of yet, no more codes. The engine still stumbles a bit on acceleration, like one cylinder isn't firing. I'm hoping a code shows up soom to lead me in the right direction. I'll start be replacing the plug wire - they're due, and have already replaced the plugs.

Thanks

Canflyboy

What is the minimum voltage of the alternator output for a 2000 windstar? I just replaced the alternator and get 13-14 volts. Alternator light comes on at times.

canflyboy,

I also changed out my wires and plugs shortly after the DPFE and all problems went away (after I figured out that I had cracked a spark plug!). Make sure you use Motorcraft or Autolite double platinum plugs. Used Bosch DP and had to change them after about 40,000 km because they were toast. Something about Ford electrical system that just doesn't like anything but what Ford makes!

how do you test the dpfe voltage while its plgged in on a 1996 windstar

No idea what a 96 looks like, mine is an 01. On the 01, I used my meter leads and poked through the wire covering to touch bare wire and then put the negative on the battery negative terminal.