2000XLT 2.5L Ranger 112000 miles, love this truck! Went to Autozone cause check engine light went on. They pulled DTC:P1401 Auxillary Emmissions Control. Malfunction w/the ODB11 reader. So I went on a witch hunt replaced the DPFE, the EGR valve, the EGR vacuum regulator solenoid, took the EGR tube off and cleaned it out replaced the hoses connected to the DPFE, disconnected the battery for twenty mins. DTC P1401 having to do with the DPFE sensor? The check engine light is still on and ODB11 reader still saying P1401 Auxillary Emmission Control. Malfunction, is there an Auxillary Emmisions Controller? Am I way off base here? Or do I need to take out my sage sticks and smudge it? Any help greatly appreciated!

 

Don't know what your problem is, but on my list of trouble codes it says: "P1401 Differential presure feedback EGR circuit high input". Makes no mention of auxilliary emissions. Looks like your on the right track with the EGR system. Sounds like you've replaced pretty much everything to do with the EGR system.

Anyone out there have any ideas on what would cause a "high input"?

Ron

 

That's what my list says too. The actual ODB11 reader has the message Auxillary Emmisions......and seeing as how i have replaced everything in the EGR system I'm stumped, check engine light wont shut off, truck seems to run fine except excessive fuel consumption and knocks just a little but that could be from bad gas. Thanx for the response Ron.

 

Since you have replaced the DPFE I would suspect a wiring problem, check for shorts and opens, also could be the PCM.

 

Yikes!!! Didnt really want to hear the PCM word but i suspect you may be right. But I'm gonna cross fingers and hope for a short!Thanx Ken

 

I would hope it not the PCM, you'll need a scan tool to do the other testing unless you find something visually. Also could be a defective replacement DPFE.

 

I am having the same problems... I replaced the DPFE sensor and It knocked out the light for 3 weeks. It came back on, so I replaced the same DPFE sensor, and it came back on four days later. What gives?

 

Diagnostic Trouble Code (DTC) P1401 indicates that Self-Test has detected DPFE sensor circuit input above the maximum.

Possible causes:

-- DPFE SIG open.

-- DPFE SIG shorted to VREF or PWR.

-- VREF shorted to PWR.

-- SIG RTN open.

-- Damaged DPFE sensor.

-- Damaged PCM.

 

Thanks for the Info, could you please give me the description for the PCM. Is the the onboard computer?

 

PCM = Powertrain Control Module (also known as an "ECM" in older vehicles).

You can think of the PCM as the main computer, or brain, of the electronic engine control (EEC) system on your truck. It is located along the upper edge of the firewall toward the passenger's side of the engine compartment.

The PCM receives input from various sensors and other electronic components (switches, relays). Based on information received and programmed into its memory, the PCM generates output signals that control your engine's ignition timing and fuel injection (among other things) through an assortment of relays, solenoids and actuators. The PCM also plays a significant role in controlling automatic transmission shifts.

The EEC system is designed to minimize emissions while optimizing fuel economy and driveability, and the PCM is programmed with that objective in mind.

 

I'm having the same trouble with my ford explorer 2002, I Idont know what happening.
Some one help me please
230235450 Km

 

Welcome, cherekmo. Give us some more information on your Explorer, such as miles, engine, how current is the truck on maintainence items?

Another suggestion: start a new thread of your own. When you tack your problem on someone elses thread, you complicate resposes to either you or the originator of this thread. Plus, your problem gets lost in discussion of the original poster's responses.

 

I am having the same problem with my 99 ford ranger, 4 cyl. P1401 popped up a while back. Now I have to get my emissions done and it won't pass, when I clear the code out, it comes back in about 22 miles... right before the reset mileage on my computer. this is my only vehicle and I need it to pass emissions. please let me know what to do, don't have a lot of money to fix things on my truck.

 

When you say that you have cleared the code, do you mean that you have disconnected the battery for 15 minutes or so and then reconnected it? If so, you haven't done anything to resolve the underlying problem.

Take your truck to an autp parts store that does free checking and see if they can pinpoint the problem so you know what to repair or replace.

 

I wanted to add my experience, since this code has been hounding me for quite some time. I tried all of the usual fixes first of course.. Replaced the DPFE with one from a junkyard. That didn't work, code came back as soon as I cleared it. Broke down (figuratively, this never actually rendered my truck inoperable. Even when I had the DPFE sensor completely unplugged) and bought a new DPFE sensor, and those things aren't cheap for a 2000 2.5L. I think it set me back over $70. That still didn't fix it. After doing quite a bit more research, I found that the EGR system could get clogged with carbon build-up which has been known to trigger this code. Just to be completely safe, I replaced the EGR valve itself, the EGR tube, and cleaned the ports they connect to really well with carb cleaner. Reset the code, and bam right back on.

I had already visually inspected all of the wires, but since the code itself makes me think electrical I decided to go a bit further. I very gently tugged on the wires coming out of the harness that plugs into the DPFE sensor. One came out with absolutely no effort, and another came out fairly easily. I suppose this could explain why replacing the DPFE sensor "fixes" the problem temporarily for some people. Handling the harness when unplugging and plugging it in might give the wire just enough contact for a little while.

The parts store wanted over $30 for a new harness, so I went around at a junk yard until I found one in which I could tug all three wires fairly aggressively and they were in there really well. Unplugged the harness, cut off enough wire to splice it to my old wires, and the problem has been fixed ever since for $2. Well, at least I have a whole new EGR system now! I guess that can't be bad for mileage.