Bad 4R44E bad,bad

[nmaineron]

Thanks Wrench,I was just playing around with it,mostly checking all my wiring to see if I possibly had a short somewhere.A friend that I confide in from time to time suggested that maybe the TPS could be the culprit because of a few experiences he has had.I had one and the resistance readings between the two were so different I figured that it couldn't hurt to try.

Getting scanned is priority 1 but at this point I am broke and have way too much invested with nothing to show for it.We don't have anyone that will scan the system for free around here.

Are the inexpensive code readers reliable?There is one at the parts store.I don't recall the brand and it goes for around $125.I could always do eBay,but which one?

 

[BrooklynBay]

Did you check the resistance of a new TPS in an auto parts store before buying one?

 

[Wrench]

Code reader

The problem with a cheap OBD 11 code reader is that it will not access the proprietory codes for your trans, just generic codes from your CEL. You cannot clear any codes by disconnecting the battery, you need a scanner with that function built in. It sure would help to get the codes read or were all shooting in the dark. Won't the place where you got the trans replaced do it for you?
Have you re-installed the original TPS to see if your old symptoms returned.

 

[nmaineron]

I went and coughed up the change for a new TPS,which made a good bit of difference.I got rid of the CEL and the flashing o/d light took quite abit longer to appear.When it did show up and I reset the system the o/d light still took alot longer to show up than before.

I know I really have to get it scanned but with the CEL light out I know all I will get is the P0741 code and no explanation why it's coming on.This to me just doesn't add up.Why don't I get a CEL when the O/D light shows up?
Especially if its a voltage a mechanical problem or a computer problem

Now that I have the truck I realize that I can't test this system the way that I thought that I could.

 

[nmaineron]

I went and coughed up the change for a new TPS,which made a good bit of difference.I got rid of the CEL and the flashing o/d light took quite abit longer to appear.When it did show up and I reset the system the o/d light still took alot longer to show up than before.

I know I really have to get it scanned but with the CEL light out I know all I will get is the P0741 code and no explanation why it's coming on.This to me just doesn't add up.Why don't I get a CEL when the O/D light shows up?
Especially if its a voltage a mechanical problem or a computer problem

Now that I have the truck I realize that I can't test this system the way that I thought that I could.

 

[Glacier991]

A CEL is REQUIRED to be set whenever an emissions related issue shows up. The OD light often acts as the equivalent of a CEL for non-emissions/transmission problems.

I have been trying to fathom out a daignosis for you, but am still somewhat mystified.

 

[nmaineron]

I went through the wiring and found nothing glaring and quite frankly the problem really doesn't make me think short or broken wire anymore.I'm kinda thinking that maybe the computer itself might be the culprit.They told me that they tried another computer but they told me alot of things.The more I look things over the more I question the service I have been paying for.

 

[nmaineron]

After changing the TPS things have started moving in my direction.The O/D light is taking 3-4 times longer to show up now.For the first time since I had the engine replaced the light didn't come on for about a twenty mile ride.Which leads me to a question or two,I have been disconnecting the battery every time I have worked on the truck.Is it possible that I have a fault so ingrained into memory that it is taking all this time to erase itself,long shot I know!

The other thing which has gotten my attention is the post on the 5R55E and the TC with the EPC being the culprit and not throwing any codes except for the P0741.That sounds very similar to what I am experiencing.Just thinking,Ron

 

[BrooklynBay]

When you disconnect the battery, the computer's memory is wiped clean. There is something called a data logger that could be connected to your vehicle while you are driving to store all of the sensor's data, and play it back on a computer. It will show you what combination of sensors were active (with intermittent glitches) at the time of the fault which triggered a CEL. There is also an attachment for a laptop that shows you a simulated dashboard with sensor outputs (voltages, frequencies, etc.) that you could monitor while driving, or could be played back from a log that is written while driving. There was a cheap version of one of these being sold in AutoZone a while ago. I also saw something like this at an auto show about 4 years ago. Glacier991, and ExplorerDMB have some threads on these. Do a search under their names, and for scanners, data loggers, code readers, etc.

 

[nmaineron]

It's been about a month since I changed the TPS sensor.I got three solid weeks of running without the O/D light showing its ugly face.Maybe 300 miles of going back and forth to work and playing around.With no noticable performance issues.Friday it shows up again!!It is still with me doing as it did before.I checked all connections and they seem fine.What do you think?Whwere should I go from here?No CEL light either BTW.Ron

 

[BrooklynBay]

Pull the code to see what it is indicating.

 

[nmaineron]

The same ole 741 code.I went to an ex Ford man that said that I should take it to a dealer and have them run it through thier diagnostics,especially have the breakout box done.He seems to think that there is a wiring issue.I can't dissagree with his logic because we all felt from the get go that the wiring had to be the culprit.Doing a good job trying to isolate a bad wire is a challenge at best and trying to mimic operating conditions is next to impossible,so I quess it is worth a try.Know where I can get a harness?

 

[Glacier991]

What is it exactly that you are looking for ?

 

[nmaineron]

The harness from the computer out for a 1999 3.0L, AT, 4x4 Ranger.

 

[BrooklynBay]

Post your request in the wanted section, and send Kbabiak a PM. He has all kinds of wiring harnesses.

 

[Glacier991]

before you do that... you should hook up the FORD trans tester and see if the tranny shifts and acts correctly away from the PCM and harness. May save you some $$.

The rotunda trans tester hooks to the harness plug on the computer and eliminates the PCM and harness from the equation. If the trans operates correctly with the tester operating it, then you know it is the harness or PCM, but...if not, then you have isolated the problem to the trans and it's electronics/mechanical parts.

I have one I loan out, with a deposit for its safe return. It retails for about $800. It is well travelled.

PM me if interested.