Ok, I am new here though I have been working on vehicles since 1973. I ran into some very confusing info looking into this and I thought it might help others.

While I am not an expert on this era, I had an issue and I think I have some clarification on occurrence. Note I have not fully proven some of this but some is. As I found out in my working tech career, often the guy on the spot could save a good tech a lot of time by pin pointing the issue if not knowing what the exact cause was.

I have had the range of CEL occur over the years (I also had an F-150 circa 1984 as I recall) and had the fun of the blink test setup.

The 95 has been problem free, a bit over 100k on it. This is the 1 ton running gear model as its a 4x4 Long Bed extended cab with a 5.8L and I make no claims as to how many other variants have the same setup. I think that is a 92-95 era but won't swear to it.

Going down the road the other day and it acted like spin out on ice, road was not that icy and the OD lockout light started blinking. That was a WTF as up to that point I had no idea it was a indicator. Hmmm. I run OD locked out around town as it shifts up and down in the 40-45 mph range and that is bad. No big deal, pretty much the same if towing, lock it out and treat it like a 3 speed.

Post all the deep dive, you also should look at the speedo and tach for clues, but the blinking stalk light got my attention.

I was almost at my destination , got turned off, turned it off, did the errand and back out and it repeated but paying more attention and yes its acting like its shifting into OD and out.

Ok, something is wrong, lets put it into 2nd and see. Blinking light yes but shifting up and down stops. Ok, I have a work around. A another errand to run further and and then home so I can do that safely.

Pulled out the code reader I had never used (never had a code to look up ) and I get no fault codes other than the I am cold (its really worth doing it cold as those codes show up and you confirm its pulling codes no shining you on).

As I have the full set of manuals I go into the wiring diagrams (that is my default, I worked on processors that control building equipment for years and that gives you the picture of what the players are and Fords is a good one).

I also did some on line looks and its amazing how even experts disagree on what those players are in the 92-95 era (parts stores also do not know the rear brake pads are 1 ton).

Simply put, the sensor for this all is in the rear differential and it feeds to the Speedo Head NOT the vehicle computer (PCM per Ford). The Speedo head is also a signal converter to feed (directly ) the Speedometer but also processes that VSS or DS into a different type signal and onto the Computer.

Many ref are to the VSS being in the trany (and or Transfer Case, I saw so much the brain is a bit muddled). That is not true for this specific series.

So, how can you get a trouble light on the Shifter Stalk OD lock out light but not a code?

That seems to be the nature of where the fault comes from. If its the Speed sensor circuit in the Differential Pumpkin or the Speedo Head (PSOM) it can do just that.

Why it does not pass a fault code onto the PCM is a mystery of Fordism maybe others can answer. As the PCM does the shifting, it clearly sees that corrupted data but seems not to be programed at all to recognize an oddity. Pretty much believes it rather than sifting it a bit.

For whatever reason the PSOM does understand its a fault and blinks light but is not setup to pass that onto the PCM (it wold seem to be an easy revert to 3rd max only). I have yet to see what it does without any signal at all (pull the plug, its too danged cold and the connector is brittle.

Reality is the PSOM only sends speed data to the PCM and does not have another signal path. Again why is ????? If you know Ford setup its probably obvious how to sort it out.

Why is this a concern? Well you need to know if the Trany going. It seems to be no, if there is a Trany issue the PCM will put out a fault code. No fault code and it points to PSOM or the VSS (various names for that per Ford but that is the most popular)

I did work on VSS type units in Generators. In that case they are the same type Magnetic Pickup unit sensing flywheel teeth to control a Governor (maintaining 1800 rpm in a Generators as close as possible is critical to Generators that parallel more than on onto a common bus). It also helps stand alone in keeping things stable so you run it all close to 60 hz.

But in those cases, the wires were molded into the body of the unit. I never had one fail. its too simple and too low voltage (there is a voltage involved but its really the pulses that are passed on, in my case 4000 hz area was common. As long as you know how many teeth are involved you can program a range. In the case of the Ford, it wold be 0 - XXXX hz. A generator program range is much narrower as a bit too much and it trips and over speed and too low creates other issues that the system will fault out on.

The VSS actually has a spin connection of some kind after the plug. I can see that getting corroded over time. The VSS is bullet proof failure wise, but corrosion wold cause erratic signals and replacing it would solve the problem. As you can't clean that spin connection it wold the the only answer.

Or your connection could be corroded (25 years is a long time that mileage does not reflecdt as corrosion does not care about mileage so much). Probably dissociating it and reinsertion it would wipe the corrosion off and No OX paste would keep ti off as well help seal it from latter creep in.

Just checking things out I spun the thing around as much as the wires allowed. Why the spin I have no idea, that is a BAD idea for the environment its in.

The next day I made a 25 mile trip, heavy load for half of it, backing up a number of times and no repeat. Suspicion is that the spinning at least temporaitly cleaned up/wiped off corrosion off enough to be ok for now.

I mentioned its cold and there is no way I am going to try to remove that unit with its two O rings in the cold, I can see it would be easy to break it (I noted more than one person reported doing so).

My take is that the key to this if there is no PCM fault codes stored it points it right at the PSOM and VSS. Which one tends to be the issue only a lot of time on Fords of that era would give you an idea. All my work years I found that this stuff tended to a common failure mode. If it faulted and the symptoms were the same you could go right to the part and either just replace it or do a quick check and confirm it was bad without doing all the trouble shooting steps.

I had the time so I would confirm it but it saved a lot of trouble shooting time and that is a technician norm. Flat rate guys might just replace it as trouble shooting can take time. In this case, if you can undo the plug its a simple OHM reading to see if the coil in the magnet is good. Its highly unlike for that to fail. Crud on the magnet itself could be an issue, shifting ring gear due to bearing issues cold be an issue, even broken teeth (though the unit does not sense ring gear teeth, it has a separate ring added onto the ring gear that gives the same looks like a flywheel setup .

I don't just assume, I also checked the trany fluid level and condition. It was good level wise and clear (I had it changed at 60k or so).

I know the E4OD had some issues though I think many were worked out by 95. Its had a pretty light duty life with only some full loads.

I sure do not want to get into a Trany Overhauls or a rear end repair.

 

one time I had that issue and it was the third brake light and no codes, year later and light is out again and this time I had multiple codes , to this day no more codes. Had a 94 a few years back and the alternator started going and it did the same thing to the od light. I take codes with a grain of salt... sometimes they work and a lot of times they are meaningless.

 

That body style ran from ‘92 - 97 in 3/4 & 1 ton models. The 1/2 ton truck changed in 1997. Those are heavy brake pads. I’m not sure what you are saying. The local store couldn’t look up rear brakes for a F-350? Parts store people only know what the computer tells them. From my understanding the transmission light was flashing because it was getting bad information and didn’t know how to control the transmission.

 

I had checked to see where the sensor was and some swore it was in the Trany, these were trany shops. Just being clear on that, there not only is a sub set of the era where the location was changed, but also a change in how the PSOM and that VSS sensor related.

For that narrow slice its a different beast and requires a different understanding if you have an issue.

As for the brake pads, yes, the store cross ref thinks there is only an F-250 light. There was a 3/4 tone that did not have the full floater.

The F-250 extended cab long bed did have the one ton axle in the rear (and the front was a variation of a 1 ton swing axle but not the F-150/Bronco type)

Point was you go to buy brake shoes and unless you have looked, you don't know they are giving you the wrong ones. So yes, it was a swap and give me the shoes for an F350. Worked fine.

There is no question that other things can cause codes to flash. This was not a code but a Shifter Stalk light and it clearly was a fault due to the bizarre shifting that took place.

Finding out where its coming from is critical and that is the back track and info. It explains why you can have a fault light and not a code.

 

The trans might have just slipped and the PCM got the signal, the trans might be in "fail safe" mode. If you truly have an issue this will not fix it, but try disconnecting the battery for a few minutes.

 

Speed sensors are in the transmission but not on these trucks. As you know know it is in the rear differential. Abounds like the transmission shops are ignorant of that perhaps because it it’s age?

Yes there were both a light duty and a heavy duty F-250. See post #6 :https://www.ford-trucks.com/forums/1...eavy-duty.html

“(and the front was a variation of a 1 ton swing axle but not the F-150/Bronco type)”

I’m not sure what that means. Starting in the early 80’s, 4wd F-250s either got the Dana 44 or Dana 50 Twin Traction beam axle. Half ton trucks used coil springs while 3/4 were leaf springs. F-350 trucks got a Dana 60 solid/ live axle.

The shifter stalk light is an indication that there is a transmission problem. My understanding is that if the electrical problem did not affect transmission operation then it would have set the engine light

 

The U Tube was a Transmission Place and well done, but totally ignorant or ignored it and they were specially talking the E4OD (not sure when that production stopped, again I am kind of a limited knowledge Ford guy - almost alwyas had a Ford but so reliable I seldom had to get deep into them)

Even Ford boards had a lot of mis-information on the setup. I can see why due to the limited era of the specific setup but as much for someone running a search and getting at least a solid basis of the players.

The axle on front is the Dana 50 IFS which I believe is the 1 ton variant? Its a hell of a lot stouter than the Dana 40 IFS on the Bronco. I did not order it, it came as part of the package. I believe that was based on it being a Extended Cab Long Bed. That is a variation not listed in the book. But it had the live axle 1 ton type in the rear vs the 3/4 ton axle I saw on vans my two brothers each had.

And I seriously disagree the Shifter stalk light has anything to do with the Transmission directly. The light is activated by the PCM, but why it lights it is where the confusion and disagreement begins and has been a part of other discussions.

The PCM does have inputs from the Transmission, I don't know if it will also give you a blinking stalk light and a MIL. It will have a logged fault. That would be a Code 628. This was not a flash fault, it went of for several minutes including coasting down hill the firs time and flat easy acceleration the 2nd time. I hauled a bed rail level load of wood two days latter. No slippage and no fault.

I certainly have seen transitory MIL (-20 and something unhappy but it did not stay in though probably a code if I had checked, no garage and no inclination to be messing around outside at those temps if no issues and it was running perfectly fine. That is part of the sort process, a MIL is not necessarily an issue unless there is a problem associated with it (which might include fuel mileage loss or ops)

In this case, there are no logged faults. Its seeing a garbage signal from the PSOM and causing the light to come on. I have no idea why there is not a code associated with that the PCM does not put into the memory. Speculative that there was no standard coding for it.

So, if you have a stalk light blink and there are no PCM held codes, its a PSOM or a VSS issue not a transmission issue. In the case of a trany slip issue, Its going to put out a code. I don';t claim to know how it codes a Transmission slippage though I have some ideas.

One area to look at in a case like this is the Tach and Speedo. If both are going buggy its the PSOM. The tach derives its data off the engine. If its just the Speedometer, then its split but points towards VSS with an uncertainty factor.

 

Let me shine a light on that. From 1993-1997 I supervised the engineering section at Ford that was responsible for setting transmission codes and flashing the OD OFF light.

When a transmission related code is stored in the PCM the OD OFF light will flash.

In these years the trans slip code could only set in fourth gear with the torque converter clutch commanded to be locked. The PCM compares the RPM from the engine speed sensor to a calculated RPM from the VSS. It calculates from vehicle speed back to output shaft speed. The ratio of engine speed to output speed must be 0.71:1, with some tolerance that I no longer remember. If it is anything else code 628 is stored in memory.

 

Thanks Mark. I thought the OD light would flash from the PCM but finding that in all the other info and years, is ????????????

The engine speed vs VSS was my guess.

Be interested in your thoughts on the no code and the light blinking as that is what I had and it looks to me that that is VSS and or PSOM.

As noted, I pulled codes that made sense for the rig not being warmed up (a bit hard to do without a 5 mile drive at these temps! (0 right now)

What does the system use for engine speed? I see a ref to that in the wiring diagram , it looks like something out of the Ignition module vs some kind of pulse picku off the engine?

I figure due to vehicle age I will be seeing a few more things show up and good to get a better understanding. OUr cooler climate is kinder on them but time and not miles still ages stuff.

 

I have heard about early Powerstrokes (pre-1999) having problems storing codes. For reasons I never could understand, the software for early Powerstrokes was written by a different department at Ford than all other software. This caused some quirks. One that I heard about but never was able to prove was that it wouldn't always set a code. It would flash the light and take preventative action, but not store a code in memory. And it seemed to not always do that.

That is one of the differences, there is no ignition module with a diesel. They use a speed sensor on the engine. I think it was on the crank, but that was a long, long time ago.

 

Not exactly. As I said before, 1 ton i.e. F-350 trucks got a Dana 60 live axle. There is no such thing as a Dana 40. The front axle on 1/2 ton trucks F-150/Bronco was the Dana 44.




You will find that there can be codes (active and stored) in the EEC-IV computer and the check engine light is not on. It’s pretty amazing all the things that it will compensate for and the the truck still runs pretty good.

 

I have a 5.8 gasoline, not a diesel, a bit of a rare one.

That was an oddity for 95, the 5.8 became the base engine for the Extended Cab long bed 4x 4 (no idea for other mix ). Prior it was the 300 and the 302 but not sure how long into the 92-95 the 300 went (4.9 and 5.0 by modern but I refer to the 5.8 as the 351 often as well). Most opted for the diesle or the 460 but the 351 was fine for the mission I had and when not lock out the OD.

Yea I had a brain zark, Dana 44 IFS for the front.

The F250 being a 4x4 and possibly the specific Extended cab long bed got the Dana 50 IFS.

 

I have seen where the 302 was only available in the LD 250 and am fairly certain neither was the 300 so that would mean that the HD base engine was the 351W. Nothing odd or unusual about that being the engine in your truck. It is likely that most F-250HD trucks were made that way.

 

Well if someone is going to argue, I pull out my data. So, here is the lineup for 1995: I keep all that stuff, I just have to find it!

4 x 2:

4.9 (300 x 6): Standard for: F-150, F-250, F-250HD - F-150 Super Cab (Extend Cab) (optional for F-250 HD Extended Cab
5.0: Optional for some, standard for none.
5.8: Standard for F-350 DRW

4 x 4

4.9: Standard for F150 and F-150 Extended Cab
5.0: Optional for the same two.

5.8: Standard for Reg Cab F-250HD, F-350 SRW, Extnd Cab F-250 HD . F--350 SRW

The following was written from memory:






Prior years had the 300 as a base engine, I drove one. It was the same 4x4 Extd Long bed.

When that changed I do not know. You rarely saw a 300, never saw a 302, everything else up here was 460 of the diesel. .

The 302 was also in that line of 4.9/5.0/5.8 and whatever the 460 was (and the diesel).

I believe that changed for the 1995 Model year and that variation became the base offering with the 5.8l. It avoided one price jump if not two.

That was also the first year of the 7.3 with the HEUI. Not sure to this day if passing that up was a benefit or not but the 5.8L has been stellar.