2000 Ranger, 2.5, 5 sp. DPFS Problem

[Guest]

Hey everyone,
Hope all enjoying the new year.

I just bought a 2000 Ranger and I'm getting the 1401 code for the DPFS. I replaced the sensor with a new one, and the code remains. I've cleared the code twice, so I have to believe there is still an issue. Is there some thing that I'm missing here? I have tried searching the subject, but have come up with very little useful information as to just what controls the DPFS, other than the PCM. Of course the scanner I'm using at the present is not displaying the voltage at DPFS, actually its not even showing the DPFS. (old snap on mt 2500) But in the scanners defence, it is updated thru 2007, so it should show what values the DPFS has. Could the lack of information mean the PCM has lost communication with the DPFS? (bad PCM?)
Anyway of bench testing the DPFS?
Other than this one issue the truck runs very well.

Any ideas?

Thanks so much for any help.

 

[adsm08]

OK, I think you mean the DPFE sensor, but yeah, hook a hand operated vacuum pump to the EGR valve and watch the sensor signal with the engine running as you pump it up. If the signal fails to change you might have PCM or wiring issues.

If the engine doesn't start running terribly or die outright your EGR valve is stuck.

 

[Guest]

Hmmm....Differential Pressure Feedback Sensor. (DPFS) Is this the same as a DPFE?

I plan on taking along the Snap On Solus tomorrow, its a little newer scanner, and hopefully it will show more information as to what's going on. I have found that the Ranger PCM's do not provide a whole lot of information in general. Is this normal, or are my scanners lacking?

 

[Earl43P]

http://www.tomco-inc.com/techinfo.aspx

Click on that link for EGR troubleshooting info.

FWIW, if the DPFE didn't fix it, the other options are the high temp silicone tubes going TO the DPFE (get them at Ford) may be cracked and the EGR solenoid itself. The EGR valves rarely go bad.

If you want to get rid of EGR altogether, look at this page http://api.viglink.com/api/click?fo....ca/EGR.html&jsonp=vglnk_jsonp_13258673326871

 

[adsm08]

Hmmm....Differential Pressure Feedback Sensor. (DPFS) Is this the same as a DPFE?

Basically. DPFE = Differential Pressure Feedback EGR, and then we usually say the whole word "sensor" or drop it off the name altogether.

Earl is right though. The valves rarely go bad on gas engines (it is quite common on diesels), it's just the easiest part to test, that's why I started there.

 

[Guest]

Thanks guys.

I installed a known to be good "DPFE" in an effort to find the problem. The system worked, kind of. Instead of having a p1408, it now had a p1401. But...shortly after installing the second DPFE, it failed as well?
When the borrowed part was returned to its original engine, it worked fine. Voltage on the good system is just over 1v. The troubled system never dropped below 4.72v, and is now at 5.12v with either DPFE installed. I haven't tried the original DPFE that started all of this trouble on the known to be good system, and that is my next chore. (ran out of time today)

Also, I did remove and inspect the EGR, and it was really clean. I can feel a pulse from one tube going to the DPFE.

Even though there is real time data being displayed, I have doubts as to the connections between the DPFE and the PCM.

MY next question is how can the circuit between the DPFE and the PCM be checked? And, does anyone happen to know the pin locations at the PCM for the DPFE?

I have read several threads on this subject over the last few days, and all seem to just stop when they reach this point. (meaning... EGR, DPFE, EVC? all have either been cleaned, or replaced, and problem still exists)


Thanks again for the help. Hopefully this will get figured out.

 

[Earl43P]

Sure thing, DPFE signal into the PCM is the BN/LG wire to Pin 65
BN/Wh wire to Pin 90
Pwr in is GY/RD wire for excitation (among other sensors).

I can send you a big file if you PM me your e-mail address (EVTM Schematics, not all, but many that you'll find useful). Click on my Username and a menu appears, Send Private Message.

 

[Guest]

Sure thing, DPFE signal into the PCM is the BN/LG wire to Pin 65
BN/Wh wire to Pin 90
Pwr in is GY/RD wire for excitation (among other sensors).

I can send you a big file if you PM me your e-mail address (EVTM Schematics, not all, but many that you'll find useful). Click on my Username and a menu appears, Send Private Message.

Well thank you for the offer and your help.
PM sent.

 

[wtatman]

The DPFE senses how much exhaust is flowing through the EGR valve into the intake manifold. If the exhaust is blocked in the intake manifold, or the exhaust tube, the DPFE will not measure any or enough flow and the ECM will set a code. A new sensor will not solve this problem because there is not enough flow to detect. I had this problem when I disconnected my EGR. I solved it by running the the EGR operating vacume line to the DPFE and blocked the rubber hoses coming up from the exhaust tube. this way when the EGR operating valve directs vacume to the EGR valve the DPFE detects the flow of air going through it instead of exhaust. The CEL has not come back on since.

 

[Guest]

The DPFE senses how much exhaust is flowing through the EGR valve into the intake manifold. If the exhaust is blocked in the intake manifold, or the exhaust tube, the DPFE will not measure any or enough flow and the ECM will set a code. A new sensor will not solve this problem because there is not enough flow to detect. I had this problem when I disconnected my EGR. I solved it by running the the EGR operating vacume line to the DPFE and blocked the rubber hoses coming up from the exhaust tube. this way when the EGR operating valve directs vacume to the EGR valve the DPFE detects the flow of air going through it instead of exhaust. The CEL has not come back on since.

I'm a little confused. What was the source of the vacuum feed at the EGR? And how was the DPFE entered into the EGR vacuum circuit?

 

[wtatman]

I'm a little confused. What was the source of the vacuum feed at the EGR? And how was the DPFE entered into the EGR vacuum circuit?

I disconnected the vacume line from the EGR valve and then attatched it to the DPFE. I left the other nipple on the DPFE open to the atmosphere for a while. The two hoses that come up from the exhaust tube I just blocked.

 

[Guest]

Well the problem has been solved!
Turned out that the gray wire with the red tracer had a broken connection at the terminal end in the DPFE connector. A quick replacemnet of the terminal has things working again. But...now the 1408 code is present.lol I'm gonna let that one go for awhile and see if it corrects itself. All of the passages are clear, and DPFE hoses seem fine. If the code doesn't go away in a couple of days I'll start thing about swapping out the EVC. Also, the voltage for the DPFE is still really high @ 4.63v, any ideas of why?


Thanks for all the help everyone; and Earl43P, I owe ya a beer!