How To Diagnose & Repair / Fix Ford EGR Circuit Failure P0401 & U1262 Communications Fault: F150

[@brandonlee8400]

Your clear and concise approach makes your troubleshooting easy to follow. Thanks for this video!

[@DrivingIntelligence]

Thank you very much! Appreciate the feedback. I hope you are a subscriber. ;)

[@scottiescott480]

​@DrivingIntelligence where did you get your electrical diagrams. I'm having same code for a Ford e150 199

[@scottiescott480]

​@DrivingIntelligence where did you get your electrical diagrams. I'm having same code for a Ford e150 199

[@scottiescott480]

​@DrivingIntelligence where did you get your electrical diagrams. I'm having same code for a Ford e150 199

[@scottiescott480]

​@DrivingIntelligence where did you get your electrical diagrams. I'm having same code for a Ford e150 199

[@Mewanrahnam575]

Your diagnostic is very methodical and conceptual.Just subscribed.

[@DrivingIntelligence]

Thank you!

[@BarryS-f4f]

Very very very good diagnostic approach

[@DrivingIntelligence]

Glad you think so!

[@nickc7494]

Excellent content, just had an issue which I had to remove the egr, snake out the port to clear carbon deposit buildup, then replace dpfe sensor and replace both 1/4 vacuum hoses which is essentially important. Unfortunately a couple task must be performed to get the egr circuit functioning properly

[@DrivingIntelligence]

right on

[@chuckythompson5031]

Dpfe sensor faulty and clogged converter on my friend's 97 F-150 5.4 l. Like a different engine now it can breathe again.Never code code for sensor and would have loved to had ya there to suggest your logic and eventually I may have put it together but good to know someone with your thought process and trouble shooting.✅👍

[@DrivingIntelligence]

glad you worked it out... I pulled my upper cats and came to find out the previous owner gutted mine passenger side! Now I only have 1 cat on the driver side! ;)

[@dyllanbabb7472]

Sometimes (rarely but happens a little more than not) that orfice tube going from the exhaust manifold to the EGR valve will become clogged causing loss of flow or none at all between the dpfe hoses. It kind of acts like any orfice like in a A/C system. The way the dpfe works is it measures exhaust pressure on manifold side hose and intake air on the EGR side hose with very minimal flow (if any)when EGR is closed through a coil winding (like a mass air flow sensor)inside the dpfe that has 12v connected to one side of winding and the reference (1-5V) wire going to pcm on the other side. (so I guess think of it more like a blower motor resistor). The exhaust pressure flows through it's hose into the dpfe and so does the intake side, when EGR is closed, they both come together and pass over the dpfe coil winding and that pressure difference is what regulates the voltage going to pcm as it passes over coil. So its taking the 12V circuit, and through a resistor, converts the voltage down low for pcm input. Meaning the more the pressure difference the more voltage the dpfe sends to pcm on a scale of 1-5 and that tells the pcm how much to open up the EGR valve. If any part before or after the hoses are clogged it'll have no signal due to no pressure difference to measure. You'll also get similar codes if that sample tube has any leaks even pin hole sizes, or if the driver side exhaust manifold is leaking at the rear of engine. Or another thing opposite of this situation is, if the orfice somehow breaks than they'll be equal pressure on both sides and could either cause this to happen or the pcm won't ever open the EGR valve because it thinks it is open. Technically when EGR valve is closed the exhaust gases (pressure) does not (should not) flow through the orfice at all but instead all of it goes into dpfe and on the other side through intake hose. When EGR opens, there becomes enough pressure from exhaust pressure and intake vacuum to pull through the orfice and recirculates the exhaust gases into the engine. So you could imagine that there's not a whole lot of exhaust actually going back into engine like most think. Just enough to keep cylinders cool (I can't remember off top of my head how this helps.) Something to do with the already burnt air fuel mixture it's cleaner, or more dense, or can be cooled quickly.

[@dyllanbabb7472]

Sorry the fix to what I was saying is changing out that $100-$150 sample tube going from the EGR valve to exhaust manifold. And a quick test to check if clogged or fully opened orfice is shooting compressed air on each rubber hose one at a time. If exhaust side hose allows air out the exhaust and not into the other hose than that's good and same thing for intake hose. Shoot air in it and either use a mighty vac to open EGR valve to allow that compressed air to go into intake so it'll be easier to listen for, or it should slip off the EGR sample tube (or buldge if hose clamped is installed) from to much pressure

[@dyllanbabb7472]

I didn't realize yours was an actual circuit failure. 9/10 times it's the dpfe. They get corrosion on the coil or it breaks. Sometimes the ports that the rubber hoses go into just get gummed up or spider webs (has happened and cause circuit failure). If you have the older style metal dpfe then ditch that one and get the updated plastic one. Ford had a tsb on this saying the metal one is .5ohms and the updated plastic one is 1ohm and should not affect drivability or the way engine runs. There was one person on Ford truck Facebook that said he went through 3 plastic ones and wasn't until he found a new metal one(discontinued and hard to find) it actually fixed his problem. It's possible he has other issues and needed one that was closer to his original pcm programmed tables. However I had a 97 with original pcm and original strategy code (tune/program not the same thing but strategy code is how you find if you have updated software or not) and the 97 f150 4.6 had the original metal dpfe and I got different ohm readings and wasn't consistent. Swapped out with plastic one and all was perfect! The ohm will be high if it's bad, most of the time, or none of it is broked

[@DrivingIntelligence]

Thanks for all that data, always great to get your input. With regard to keeping the cylinders cool, the purpose of the EGR circuit is to keep combustion temps down to prevent the formation of NOx, oxides of Nitrogen, which is a pollutant. Very important for our environment.

[@DrivingIntelligence]

@@dyllanbabb7472 thanks

[@DrivingIntelligence]

@@dyllanbabb7472 more good info

[@christinefisher877]

So I just watched your video and I am wondering if you completed the drive cycles before you rescanned for codes? Seems to me that when you erase the codes, they are not going to reappear until the drive cycles are complete and readiness is attained.

[@DrivingIntelligence]

Good question, sometimes faults show up immediately and sometimes they require drive cycles to show up. In either case, I made sure the errors did not return once the repair was completed.

[@1981zamora]

Great video easy to understand

[@DrivingIntelligence]

Thank you 🙏

[@dyllanbabb7472]

Your seatbelt is because your running diagnosis with driver side seatbelt unbuckled and same goes if running codes (key on engine off) and you get oil pressure gauge/sensor code too. I've also gotten window circuit codes if I run diagnostics with the window in any position except up (but not on every vehicle) and door switch codes may appear if running codes with door open. Just throwing that out there

[@DrivingIntelligence]

Thanks for that info Dyllan

[@caradu9973]

Great video very detailed Thank you

[@DrivingIntelligence]

You’re very welcome

[@BrettDarien]

I had a P1406 code on my 00 F150 4.6L. Replaced the DPFE sensor and thought all was good but now I'm getting a P1400 code. Is my new sensor faulty?

[@DrivingIntelligence]

Hi, your codes don't necessarily indicate a problem with the DPFE sensor. Have you followed my tests to isolate the problem? Your EGR system could be plugged and need cleaning.

[@BrettDarien]

@DrivingIntelligence The P1400 code seems to indicate low voltage. It didn't show low voltage before I replaced the DPFE sensor. All hoses are clear, I even replaced a hose that's going to the EGR valve. It doesn't seem to be affecting performance, but it just bothers me that the engine light is on.

[@DrivingIntelligence]

@BrettDarien have you checked the EGR for plugging and proper function?

[@BrettDarien]

@@DrivingIntelligence I don't have a vacuum pump like you have in the video. I'll see if I can find one and maybe do some more testing over the weekend.

[@DrivingIntelligence]

@@BrettDarien good call, if your EGR is plugged and not opening properly, or the plugged areas are limiting exhaust flow, you will get a bad voltage reading.

[@rescatepreventivoviales7995]

Very good video😊

[@DrivingIntelligence]

Thank you!

[@en439]

2021 ford ranger. Bucking and surging. New spark plugs and a ton of sea foam did not fix. Dpfe egr sensor and hoses fixed the problem. $150.

[@DrivingIntelligence]

Glad you got it sorted out

[@PRIC3]

Where do you get you data sheets or pictures to see how everything is connected

[@DrivingIntelligence]

I use Ford repair manuals or find them on internet.

[@flowersfam3462]

I wish you were in Georgia to look at my vehicle!😊 I like learning and fixing my vehicle repairs, but I do wish I had a lift to do repairs underneath my 2000 ford expedition 4.6L V8 Triton XLT. By the way, do you know where I can get valve body parts for my vehicle?

[@DrivingIntelligence]

A lift surely helps, but my problem is my Mustang is stored up there making room for my other projects! As far as valve body parts are concerned, I assume you have a 4R70W tranny. This playlist shows how I resolved OD Shudder by using many parts that improve transmission performance and life. The first video shows most of the parts I used to improve valve body performance: kzbin.info/aero/PLGNsbVXzRfZM6WpCF862q4DlkyatzFIMz&si=jXFGBHlIvog_-ku3

[@flowersfam3462]

@@DrivingIntelligence Yes I do have a 4R70W. Thanks for the playlist link.

[@DrivingIntelligence]

Sure thing, let me know if you have any other questions

[@flowersfam3462]

@@DrivingIntelligence I was watching all the videos in the playlist and it's good to see the parts that I will need and actually find them. I wanted to know where to get a compression spring tool to use when I do my overdrive servo, reverse servo, etc. or did you make one?

[@DrivingIntelligence]

@@flowersfam3462 Glad you found the playlist useful and if you buy through the AMAZON links in my description it helps support my channel without costing you any more. I added the link to my video for the tool I used, but that company is either out of business or out of stock. I found this listing on the internet, but I have not used this tool: www.freedomracing.com/307-251-servo-piston-remover-installer-t92p-70023-a.html?___store=default&gad_source=1&gclid=CjwKCAiA1-6sBhAoEiwArqlGPmhvt1SuH5kP0Ui5YI-yRELcMJpDOp0H59DnjT9duXN3gwjIEN784xoC2VoQAvD_BwE

[@devinbailey6576]

I have the same problem on my van spent 1700 at the shop and still there. I’m going to try this.

[@DrivingIntelligence]

Thanks for watching and your comment. Please give me an update after you do your tests.

[@DrivingIntelligence]

ever try the tests in my video? I am very curious...

[@DrivingIntelligence]

Get your van resolved?

[@41BeachComber]

I have a 4.6 with the same code. Replace the egr valve and cleaned the lines and replaced the other part with the plug and two lines going into it. Yet I get same code. Been checked by a shop, they say it all works good. So I just leave it alone. I use the BlueDriver also.

[@DrivingIntelligence]

Sorry to hear that. Did you perform all the tests I show in this video? Shops that say, it works, no problem with a continuing check engine light are not worth the time or expense. Do you have any other codes to go along with the P0401?

[@41BeachComber]

@@DrivingIntelligence no. Just that one code. Truck has over 287000 miles on it too.

[@DrivingIntelligence]

@@41BeachComber I suggest you try all my troubleshooting steps to see if you can isolate the problem area. Get back to me once you have performed those steps.

[@taneesescu]

Was getting back pressure code. replaced sensor and exhaust tube which was 241k original part and clogged. after replacing i now get rhe u1262 spc data link in the hybrid electronic cluster. its on 02. ay suggestions. im seeing stuff all over the map on what it might be

[@DrivingIntelligence]

Did you only have one code? You replaced your DPFE sensor? Do you continue to have other codes, and are you sure you cleared all codes after performing the repairs? Try this trick to reset the ECU and let me know what happens: kzbin.infom9xQSaeyZ6o?si=ng9SCgYsjVZ2fW6B

[@taneesescu]

@@DrivingIntelligence discovered the code is a generic bus error. Something cant communicate with the PCM or vice a versa. It was the aftermarket radio back up camera that I strongly believe is the culprit. Went back to my logs and the code was always present since I got this truck 6 months ago.

[@DrivingIntelligence]

@@taneesescu what year is your truck? And just to confirm, your only DTC is U1262?

[@taneesescu]

@@DrivingIntelligence its an 02 7.3 and it has side passenger airbag and another airbag and that is it. Yes 3 codes

[@DrivingIntelligence]

@taneesescu can you please send me all 3 codes? Hard to assist without that information

[@dogecoin4085]

Is are supposed to run in through one tube and out the other??

[@DrivingIntelligence]

Hi there, don’t understand your question my friend. Can you rephrase?

[@JustBoogieProduction]

Can a faulty cat cause a po401 code?

[@DrivingIntelligence]

In my experience, I don't see any connection betweencP0401 and a faulty cat. If the cat is completely clogged, perhaps?

[@BigHRepair]

Highly doubt it. That's gonna be more of like a.p0420 p0430 code

[@Magnuss0724]

My sensor melted off. What does that mean

[@DrivingIntelligence]

Are you referring to your DPFE sensor?

[@Magnuss0724]

@@DrivingIntelligence yes I literally melted like wax

[@DrivingIntelligence]

@@Magnuss0724 My thought is that it internally failed and allowed exhaust gases to flow through the sensor, or one of the tubes going to the sensor is plugged. Remove the rubber hoses and try spraying carb cleaner down the tubes to make sure they are free and clear.

[@joeortiz6941]

I need p1405 senser replace

[@DrivingIntelligence]

Always remember a diagnostic trouble code indicates a problem with the sub-system, and not necessarily the sensor that is indicating the problem. In this case, a P1405 can be caused by one of the following: 1) Damaged, disconnected, or plugged DPFE sensor upstream hose, 2) Faulty DPFE sensor, 3) Malfunctioning EGR valve, 4) Wiring issues in the DPFE sensor circuit, 5) Leaks in the EGR system, 6) Clogged EGR passages, 7) PCM failure (rare). Try the tests I show in this video to isolate the problem.

[@michealhernandez2004]

Now he knows what's going on.

[@DrivingIntelligence]

thank you

[@jimleffler7976]

I replaced mine ,still having issues so I'll check the wiring

[@DrivingIntelligence]

What did you replace?

[@jimleffler7976]

@@DrivingIntelligence the EGR valve and the dpfm

[@DrivingIntelligence]

@@jimleffler7976 good luck with your testing

[@carlbutler4684]

I need you to look at my car

[@DrivingIntelligence]

Where are you located?