DPFE Sensor

Tiny
SIMPSC
  • MEMBER
  • 1999 FORD RANGER
  • 2.5L
  • 4 CYL
  • 2WD
  • MANUAL
  • 140,000 MILES
I have a 1999 Ford Ranger, 4 Cylinder, 2.5 liter. I was having trouble with it on startup and sputtering until I got going. I found that if I disconnected the tube from the EGR valve things ran much better. I found the EGR valve was leaking so I replaced it but the problem still exists. I am pretty confident that I tested the EGR solenoid thoroughly and it is ok. I started looking at the DPFE sensor and have a question about the voltage. According to what I read, the bottom wire is the reference voltage and it is 5v. The middle pin is ground and I verified that it is good. The top pin should be the signal wire and should be about 1 volt until the pressure changes and it should rise along with the pressure. However, the signal wire has a constant 5v. I assumed this meant the DPFE sensor was bad but when I removed the wiring connector from the DPFE sensor, I found that pin 1 still had a constant 5v. I checked and there is no continuity between the signal pin1 and the 5v reference pin (trying to rule out a short in the connector). Now I am wondering if this constant 5 volt from the PCM is normal or is the PCM supplying 5v that it shouldn't. Any help would be appreciated.
Saturday, December 19th, 2015 AT 3:36 PM

16 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
With the connector disconnected, it should only have 5v on one wire, the gray/red wire.
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Saturday, December 19th, 2015 AT 7:26 PM
Tiny
DAVIDPARTIN
  • MEMBER
  • 1 POST
  • 1998 FORD RANGER
Computer problem 4 cyl Two Wheel Drive Manual 170, 00 miles

Insufficient EGR Flow code - I have replace the EGR Valve and backflow sensor. Cleared the code and it comes back on after about 100 miles. Runs rough when first started. Any suggestions?
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
Hose/pipe coming out to the exhaust manifold into the EGR valve has carbon deposits in it, causing a blockage. Clean properly to resolve MIL.

Thanks for using 2CarPros. Com!
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
JOE BLOUGH
  • MEMBER
  • 16 POSTS
Did you check the DPFE sensor? I had the same issue, changed it and there was no more problem.
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,271 POSTS
Here is the location of the DPFE sensor so you know what it looks like.

Check out the diagrams (Below)

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
CARDETAILER18
  • MEMBER
  • 5 POSTS
  • 1996 FORD RANGER
  • 196,600 MILES
I have a 1996 Ford Ranger Super Cab 2.3l 4 cyl. 5 speed truck. I have had the check engine light come on 4 times in the past 2 weeks and every time it was code P0401 or Exhaust Gas Recirculation Insufficient Flow. The truck wasn't running poorly, but I decided to change the EGR valve. Right after changing the EGR valve I started the truck and it was running roughly. I then changed the spark plugs and wires and it was still running roughly, so I put the old EGR valve back on and that didn't fix the problem either. I then put and EGR sensor on my truck and that didn't fix the problem either. I then drove it home from the shop and when it was idling in my driveway it was idling high and wouldn't ever go down. The fan was also not shutting off. What is wrong with my truck? Do I need to replace the EGR solenoid? What else could be the problem?
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,055 POSTS
When you replaced the EGR, did you check to see if there was a carbon build up in the intake?
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
CARDETAILER18
  • MEMBER
  • 5 POSTS
No I did not.
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,055 POSTS
Check that to see if there is blockage. Just remove it and check. Let me know what you find.
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
CARDETAILER18
  • MEMBER
  • 5 POSTS
If there isn't any carbon build up what do I need to do next? It is a lot harder than it sounds to take off the EGR valve.
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
CACHER
  • MEMBER
  • 7 POSTS
  • 1994 FORD RANGER
  • 4 CYL
  • 4WD
  • MANUAL
  • 17,800 MILES
Yes, I have reviewed engine codes here, just wanting to make sure I am correct in my findings is all, and it sure seems everybody here has more than enough brainpower to assist with my check(s). This place rocks.

Ok, went and did a few tests with my Sunpro CP0915 scanner on the 1994 Ranger I-4.

Key On Engine Off testing gave me these blinks with the tone; (possibly 1-1-1 to equal the three, and not the 111 code for letting me know that no problems were found) 3-3-5, 3-3-5, 1, 2-2-4, 2-2-4.

A. I am quite sure the 224 is the DIS primary circuit failure in Coil #1, 2, 3, or 4. I have replaced both coil packs, put on new wires, and new plugs a month ago. Why not it has 178K on it and I have changed plugs and wires a few times, but never the coil packs. Ufortunately as of this typing truck is still running in failure mode (998 according to the tester and manual), and idles at about 500rpm, although nothing has happened, and I have been driving it for a month like this since the above parts change, and all is ok.

B. Sunpro manual says 3-3-5 is the EGR Valve Position (EVP) sensor, or EGR Pressure Transducer (EPT)-signal voltage higher or lower than expected (Key On Engine Off Self-Test).
WHAT the heck is this stuff/thing and where is it?
I have a feeling that if I replace this my idle will return to normal, and all will be ok.

C. Thanks to all who take the time to read through this for me and offer any assistance.
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
ARTICLE BEGINNING TESTING PORTED EGR VALVE 1. Check vacuum hoses for correct routing. Connect a vacuum gauge directly to EGR vacuum source. With engine running, open throttle. If gauge indicates vacuum, EGR vacuum supply is okay. 2. If gauge indicates no vacuum, EGR vacuum port is plugged. Disconnect vacuum hose at EGR valve, and plug hose. Connect a vacuum pump to EGR valve. 3. Start engine. Apply 6-10 in. Hg to EGR valve. Engine should run rough or stall and EGR valve should hold vacuum. If engine speed does not change, check for plugged EGR passages or faulty EGR valve. ELECTRONIC EGR VALVE 1. Connect vacuum gauge to EGR valve. Start engine. Ensure there is less than 1 in Hg to EGR valve at idle with engine at normal operating temperature. 2. Install tachometer. Disconnect Idle Air By -Pass Valve (IABV) harness connector (if equipped). Disconnect and plug vacuum hose to EGR valve. Start engine and idle in Neutral. Note idle speed. Using a hand-held vacuum pump, slowly apply 5-10 in. Hg to EGR valve. 3. Engine should either stall or idle should drop at least 100 RPM. Idle speed should return to normal when vacuum is released at EGR valve. Repair or replace EGR valve if none of the conditions occur. NOTE: EGR Vent Solenoid (EVRV) allows a small vacuum signal (less than 2.5 in. Hg) at idle.


https://www.2carpros.com/forum/automotive_pictures/62217_ranger_4.jpg


8) Code 335: Verify KOER Codes Code 335 indicates DPFE sensor is out of self -test range (2.6-4.2 volts) and may be faulty. DPFE system can detect lack of pressure in exhaust system. A garage exhaust ventilation system, installed during KOEO SELF-TEST, may cause DPFE sensor to generate Code 335. Remove exhaust ventilation system. Repeat KOEO SELF-TEST. Service codes as necessary. If no codes are present during KOEO SELF-TEST, complete QUICK TEST . If Code 335 is present during KOEO SELF-TEST, go to next step. 9) Check DPFE Sensor Pressure Input Hose Remove pressure feed tube from DPFE sensor. Inspect tube, including DPFE inlet, for blockage. Repair if necessary, and repeat QUICK TEST. If no blockage is found, go to next step. 10) Measure VREF Circuit Voltage With ignition off, disconnect DPFE sensor wiring harness connector. Turn ignition on. Measure voltage between VREF and SIG RTN terminals at DPFE sensor wiring harness connector. If voltage is 4-6 volts, replace DPFE sensor and repeat QUICK TEST. If reading is not 4-6 volts, go to CIRCUIT TEST C .
Look at the back of the engine, there is a small stainless flex tube that runs to the egr, and egr possition sensor, there are two small hoses attacheched to it. and an electrical connector. See if it has melted, common problem!
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
CARDETAILER18
  • MEMBER
  • 5 POSTS
It also had code P1401 come on when I started it at one point during the repairs.
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,055 POSTS
I'm sure it is a pain. Make sure there are no vacuum leaks around the EGR
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
MARTIGREEN
  • MEMBER
  • 1 POST
  • 1994 FORD RANGER
  • 4 CYL
  • 2WD
  • MANUAL
  • 169,000 MILES
My ford ranger idles real bad an has no power. I can't get out of first gear. I replaced the plugs and wires and did not fix the problem. I had a valcum line go bad that connects from the egr valve pressure censor to the engine. I put another one on and it still does it. Do I need to replace the EGR valve pressure censor? When the valcum line went bad that is when I started having this problem. Please help.
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Open up the EGR valve and clean it and its passages, also check the idle air control valve/motor/ISC and the throttle position sensor
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Wednesday, May 1st, 2019 AT 5:21 PM (Merged)

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