i have a current body style '04 (i guess they changed half way through the year?) f-150 with a 5.4L 3V Triton with the plastic intake manifold under the hood and have a p0401 code and have searched everywhere on this forum to find where the dpfe is so i can trace the vacuum lines to make sure they are not leaking, test the dpfe etc, i know what to do, just can't determine where the dpfe is so i can get started. all the threads are for older 5.4's with the dpfe on the top/driver's side of the intake manifold.

it looks like it could be on the firewall next to the brake booster but that looks more like the egr valve to me...

any help is greatly appreciated, thanks.

 

bump for help please!

 

I don't recall that the 5.4 3V engine had an EGR/DPFE system on it back then; does your truck have an EGR tube running from the exhaust manifold up to the top of the intake?

 

With variable cam timing, the 5.4 3V has internal EGR; it doesn't use a DPFE, EVR, EGR valve/ESM, etc. The cam phasers can accomplish EGR by varying the valve overlap.

 

That was the Vapor Management Valve you were probably looking at....for the Evap system.....

 

ok, well, that explains why i was unable to locate it...

can anyone tell me how to solve my p0401 code?

thanks for the input, i really appreciate it!

 

That's a first on me for a 5.4 3valve...I just dug around the PC/ED and didn't find anything of use... ..are you sure about the code number??? Doesn't seem possible for a variable cam timing engine........any other symptoms? Is the CEL on?

 

yes, the cel is on, as is the little wrench light... mileage on the truck is 135k kilometers... for some reason though, i am unable to clear the code with my obd2 scan tool. it is a complete mystery to me. i am starting to get frustrated with this...

the truck doesn't seem to have any get up and go when you put your foot down. it won't rev past 4k rpm and it feels like a misfire to me. the plugs were replaced 20k km's ago so i can't see it being them.

i really don't want to take it to the dealer.

 

You may want to get a second opinion with another scan tool. How do you have an insufficient EGR flow code on an engine that doesn't have EGR (or a conventional EGR system, rather)?

 

If the wrench light is on the problem is in the electronic throttle control which may also explain the limited power....you need a better scan tool to read the codes, something that reads all of the codes, not just the OBDII stuff......It might be worth going to the dealer to get the initial Diagnosis.....

 

This sounds like what you are describing...


RPM Guard w/Pedal Follower

In this mode, torque control is disabled due to the loss of a critical sensor or PCM fault. The throttle is controlled in pedal-follower mode as a function of the pedal position sensor input only. A maximum allowed RPM is determined based on pedal position (RPM Guard.) If the actual RPM exceeds this limit, spark and fuel are used to bring the RPM below the limit. The ETC light and the MIL are turned on in this mode and a P2106 is set. EGR, VCT, and IMRC outputs are set to default values.

 

sounds fantastic, i guess i'm off to the dealer... i really appreciate you sharing your knowledge guys. i'm a noob to fords and v8's altogether. i'm used to sewing machine 4 bangers.

 

ok, ok, got a different obd2 scanner and here are the codes:

p0113 intake air temperature high circuit input
p0118 engine coolant emperature circuit high input
p1298 injector driver module failure
p1509 (not listed in my book, but i believe it is something related to the iac)

anyone got any ideas on where to start, or if i can fix any of this stuff myself? i'm beginning to think i should just take it in to the dealer.

thanks for any input.

 

Take it to the dealer...you are in over your head.....

 

well, most of it sounds electrical/ecm related, but i'm not opposed to tackling something new if i have the means. i'm not completely incompetent as i've been playing with cars for over a decade now... i'm just unfamiliar with fords. i'm just looking for an explanation in more detail of what these codes are. the p1298 is fairly straight forward, the others are probably just sensors that need to be replaced...

any more thoughts?