MY first post has to be a call for help. I'll do a formal intro after I get this van back on the road.
Here's whats going on:
2005 E350 Super Duty 5.4L Base model ran fine Wednesday night. Thursday morning it started up like normal but idled rough. It wouldn't rev over 1500rpm, MIL and wrench light came on. Parked it.
Friday I got around to reading codes. P2107 and P2110. After some googling I suspected the TPS. I couldn't verify it was bad as all test procedures referred to a 3-pin TPS and mine is a 4-pin. Also I can't find a wiring diagram. So I replaced the TPS. No joy. Same rough idle, now zero response to the accelerator and now 3 codes, P2104 P2107 and P2110.
Fast forward to last night when I have more time to work on it. I borrowed a nicer scan tool that lets me watch live data while the motor is running. Its showing a constant TPS% of 18.8%. There is also an ABSLT TPS% at constant 26%. So here's my first question: are these two TPS% readings coming from the 4-pin TPS, the TPS and the APP, or something else entirely?
I was grasping at straws at this point so I replaced the dc motor on the electronic throttle body. Still no joy, same symptoms, same 3 codes. And that's where I left it last night. So my big question is am I correct in assuming that I'm left with the PCM or the wiring itself? And does anyone have a wiring diagram for this motor?
Thanks in advance.

TL;DR: codes P2104, P2107, P2110
rough idle, no response to accelerator pedal
replaced TPS and throttle body motor
help please

 

Hi Rocketgirl, and welcome to FTE!

I don't have a shop manual for your van, but my guess is that you have a wiring issue. I'd suggest taking a good look at all of your connectors between the throttle body and the PCM. I'm not great with wiring, so hopefully someone else can give you some more specific advice.

Generally replacing the PCM is the absolute last step in a diagnostic tree after everything else has been ruled out. It's rare for a PCM to fail, but it can happen.

 

Thanks for the reply Tom. I will try to find the other ends of the wires at the PCM tonight. Thanks for fixing the thread title too.

 

No problem. Wouldn't do any good to have folks thinking you're driving a Chevy!

 

Read both pages here, might be the same issue.

Electronic Throttle Control - Ford Expedition Forum

 

Last night I traced the wires from the TB motor and the TPS back to the PCM. I didn't find any shorts or damage.
A friend who is a former Ford tech came over and looked at it. He suspects that the accelerator position sensor is the culprit. Looking at the live data on the scan tool shows the 3 APP sensors to disagree by as much as 18%. Also pedal on the floor only reads about 75% and all the way out reads about 20%.
So even if the APP isn't the cause of this particular problem, its not working well anyway. Now I'm off to find and accelerator assembly.

 

I'm not convinced the APP can cause that, but without the service manual in front of me I can't say for sure. If that's where he's getting his info from you may be on the right track.

 

My friend got me some documentation that supports his diagnosis. Its a great write up on the ETC. I'll scan it and try to post it when I get home. What's the best way to post a pdf here?

 

You may be able to add it as an attachment. If not you can send it to me and I can attach it for you.

 

I hope the attachment works...

 

It works great, thanks for posting! I'm gonna add this to the tech folder.

 

Well I finally got the new accelerator assembly on Saturday. Bolted it up and plugged it in and still no fix. Symptoms remain the same, rough/searching idle and no response to accelerator. Also same codes P2107, P2110 and P2111. I did let it idle long enough to warm up and "learn" the new sensors.
My plan now is to chase the wiring between the accelerator and the ECM. If that checks out then I guess I will have to get the van towed to a dealer to reflash the computer.
Any other suggestions?

 

I wish I had some better advice, but electrical issues can be a bit beyond me.

 

For more input, You might want to try posting your vehicle situation here:

Modular V8 (4.6L, 5.4L) - Ford Truck Enthusiasts Forums

Hopefully, you"ll get it squared away without having to drag it to the dealer.

 

I can move the thread if the OP wants.