The VSS should be OK if you were reading MPH from the rear differential via OBD.

Tell me how you found yourself at section 308-07A?

I am not 100%, but aren't there speed sensors on the 4R100 as well?

Look in section 307-0X for reference to the TSS or maybe the OSS. I am a ZF6 guy, so I am not 100% sure on those, but seem to recall them.

 

I was using the instrumentation diagnostics section - speedometer not working (non-motorhome). Flow chart said if speedometer didn't agree with AE, to refer to one I referenced. I'll check the one you mentioned, thank you .

This is my first automatic 7.3, also. All of my others are 5 speeds, so this truck is a learning curve to me.

 

Do you have the enhanced Ford package with AE? If so, you should be able to pull codes from the GEM/BCM. And the transmission, if that is even a module. I also have a ZF6, so I cannot help you there. I am using AE on a Honda right now and I can see the "commanded gear". See if you have that on yours. You can see the commanded gear to see if the truck is even telling the transmisison to go into 3rd. If the "commanded gear" skips from 2 to 4, then your transmission is probably not the source of that issue.

P0500 directs you to PC/ED, which is the Powertrain Control/Emissions Diagnostic manual. P0500 is on page 5-121 in the PC/ED manual for Programmable Speedometer/Odometer Module (HB). I suggest following that flowchart. I have the manual in PDF form if you need it.

You were directed to pinpoint test B in section 308-07A of the factory service manual (not shifting betwen 4H and 4L correctly). It is a weird place to include the test for P0500 but it looks to be for a 4ABS model, not RABS. Forgive me if you have mentioned this, but which system do you have? 4 wheel ABS, or rear wheel ABS?

 

Honestly, I assumed the truck had 4 wheel ABS but haven't verified that. There's an ABS block behind the driver's side headlight if that is any indicator.

 

You probably have 2 wheel ABS, but you can check easily by seeing if your front hubs have the ABS sensor wires in tact or if they have been cut.

FTE'r Unleashd shared his private stash of PDF manuals with me a while back in this thread. I am not sure if he wanted the link public or not, so I have sent it to you via PM.

The FSM can be a bit cumbersome to navigate. I also purchased the PDF version and found them to be more difficult to navigate than the FSM program, but hopefully you will be successful. The issue you are having, I don't know which direction to point you toward. Hopefully you will find something in the PDF version of the manual.

 

I buy a lot of PDF manuals. I have a free version of Foxit PDF which allows you to bookmark PDFs. Bookmarking helps a ton, the PDF manuals are darn near useless without that. I went through and bookmarked all of the important sections of the manuals I frequently use. It is worth its weight in gold when I can pull up a PDF on my phone from Google drive and navigate to right where I need to whenever I am working on something without my laptop handy.

 

Your absolutely right about the weight in gold. That is the reason I bought the PDF version, so I could carry it on my tablet and phone just in case I needed it. I still have it there, but you are right again that without bookmarks it is difficult to work with.

I hope that between the FTE advice, the PDF and the FSM program we can get cfpinz some help soon.

 

Thank you both, I appreciate the help.

I'll check the front hubs for ABS wiring tonight if I get the chance, and I also noticed the ABS light doesn't light up when I'm waiting for the truck to start. So, it's hard to tell what all this critter has got going on. I bought it for the wife to use feeding cows and to drive in bad weather as a beater, just want it to be safe and somewhat reliable - it'll never go more than an hour from home most likely. I keep my expectations pretty low, after all it's a 22 year old feed truck.

 

So it looks like the truck had 4 wheel ABS at one point. The calipers have the remnants of a plug on the top front surface and there are wires up to the rubber brake hose junction block at the frame rail - so I'm assuming the ABS wires have been ripped off over the years and I'm not about to go replacing all that mess. I went through the FSM flow chart for inop speedometer/P0500 and it keeps directing me to the 4wd section and a no shift 4wd flowchart - my 4wd operates just fine. Also noted there are no ABS or Brake lights on at startup - so I'm assuming the bulbs are gone. Big deal.

The truck has the 2 sensors on top of the 4R100, TSS and OSS, from what I gather. When I go through the diagnostic chart for the skipped 3rd gear it references a breakout box, which I'm not familiar with. Anyone have an explanation for what a breakout box is?

I really don't care about fixing all the little nitpicks on the truck, as it does what it was hired to do at this point - feed cows. I would like to get the trans shifting correctly, and it'd be convenient to have a working speedometer but it's not necessary. I'll likely have the local trans shop run a diagnostic on it for grins as far as the first issue, but was wondering if there is a way to test the speedometer assy to see if it's faulty? I don't mind spending $100 or so on a cluster if it's needed, but don't care to if that's not the problem.

Thanks to everyone here for the help, I appreciate it very much.

 

A breakout box is a box that plugs in between two halves of a connector to allow you to easily probe circuits with a multimeter. Backprobing the connector achieves the same thing without having to invest in new hardware.

 

I hear you on the ABS light being out and not a concern, but perhaps this is a clue to what the problem is with the speedometer. There seems to be several different paths to take, each with their own challenges. Since this is not a daily driver, you are lucky in the way that you have a choice to chase the rabbit or let the rabbit go.

As for back probing, here is a video that FTN posted a while back that does a good job at explaining it.

https://www.ford-trucks.com/forums/1...l#post19365825

 

The older I get, the less patience I have to chase things - that rabbit's on his own.

Thank you both for the explanation, I'll invest a little more time into it but I'm ready to move along.