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Hi, new to the forums, although I've looked around here for answers in the past. What I have for you today - I've got a 96 F-250, 5.8l with an E4OD, and it's got some issues I thought for sure were linked to the speedometer. And before anyone asks, yes I've looked around the forums and can't find answers this far in.
The speedometer jumps, doesn't go above 30, just bounces around below that. It's got hard shifting, the ABS light is on, the OD light doesn't flash. It does have an aftermarket trailer brake that isn't hooked up electrically anymore but is still on a line from the brake reservoir, not sure if that affects this at all. The Odometer does move and count as it should, on both the new and old PSOM.
I've replaced the VSS (twice), checked all the wiring up and down, got electrical cleaner and cleaned everything I could. Replaced the PSOM, still no luck. Checked the exciter ring, no issues. Unplugged the ABS module behind the glove box and ran it without it, no change in results. I'm at wits end. Anybody have advice for me? Thanks in advance.
I had a transmission issue in the past with my 94 and it was related to corrosion on the ECU connector, where it plugs into the ECU.
Currently don't have a code scanner, and can't really take it anywhere to get checked. I bought the truck a month or two ago, found it in a field. Had been sitting the past 3 years. Surprised it fired up, drove it home and started replacing fluids. Can't pass inspection right now so have to do all the work at home. And ideas where I could get a good scanner for cheap?
In this case I do not think a scanner or code reader will help any.
A scanner would be a little over kill as they run $200.00 up.
A good code reader would be all you need for now.
Here is a good one, the INNOVA-3145-Ford-Digital-Reader for about $30.00 at most auto part stores and on amazon.
Just click on the little Amazon image beside it below.
Attachment 285410
But as I say a reader is not going to help much with your rear end problem.
Sounds like you have a gap issue and that could be the bearings.
The wiring from the rear end to the modules if bad may cause this also.
Someone may have changed the VSS before you got the truck and now the gap is to large.
The VSS very seldom goes bad. The only way it can be bad if someone break it or it loses it magnetism.
No moving parts.
Someone may have changed the VSS before you got the truck and now the gap is to large.
The VSS very seldom goes bad. The only way it can be bad if someone break it or it loses it magnetism.
No moving parts.
How do I check the gap, and fix it if that is the issue?
Could not find what I was looking for on that thread, however I did find one of your posts on a different thread that shines some light:
Originally Posted by subford
I would unplug the PSOM and the RABS module and recheck the voltage.
If the voltage is right with the PSOM unplugged then I would replace the PSOM.
Here is the gap measurements, K11.
K11 MEASURE RABS SENSOR AIR GAP
Remove rear axle differential cover.
Measure the shortest distance from the RABS sensor pole piece to the teeth on the RABS sensor ring.
Rotate the axle 60-90 degrees.
Repeat the two previous steps five times for a total of five measurements.
Are all measurements between 0.127mm (0.005 inch) and 1.14mm (0.045 inch) and within 0.254mm (0.010 inch) of each other?
Yes
GO to «K13».
No
Measurements are not between 0.127mm (0.005 inch) and 1.14mm (0.045 inch). CHECK for foreign material under RABS sensor mounting flange and on carrier housing. REPLACE RABS sensor. GO to «K12».
Not all measurements are within 0.254mm (0.010 inch) of each other. REPLACE RABS sensor ring. GO to «Pinpoint Test S» to verify concern is resolved.
What I'm seeing is take the differential cover off and measure it that way. Assuming that's what's wrong and that there's an air gap, what would cause that? Would it be the exciter ring, the bearings. etc. Whenever I get the time I'll get the cover off, replace the fluid and look around inside, but is there anything I should be looking out for in specific?
In this case I do not think a scanner or code reader will help any.
A scanner would be a little over kill as they run $200.00 up.
A good code reader would be all you need for now.
Here is a good one, the INNOVA-3145-Ford-Digital-Reader for about $30.00 at most auto part stores and on amazon.
Just click on the little Amazon image beside it below.
https://www.amazon.com/INNOVA-3145-F...de+reader+obd1
But as I say a reader is not going to help much with your rear end problem.
Sounds like you have a gap issue and that could be the bearings.
The wiring from the rear end to the modules if bad may cause this also.
What ever scanner you get it needs the capability to read "Enhanced" codes
Haven't had a chance to test it out yet, but here's the diff prior to brake clean. Nothing really looks broken or out or place, or dented in the slightest. Everything looks right. Haven't replaced the tone ring, if new fluid doesn't solve the issue that'll be the next step.
Aside from the check plug being filled with what looks like silicone? (will be cleaning it before putting it back in) Will post back with results.
Quick update. Power's currently out in my neighborhood, so took it as a chance to test everything out. ABS light still on, speedometer still unresponsive, shifting still buggy. The speedometer will jump between 0 and 20, sometimes when I'm sitting still and not moving with truck in park. So at this point, will the general consensus be replace the tone ring or could it be anything else? As stated in original post, new PSOM, new VSS, checked with ABS Module plugged in and unplugged, maybe unplugged the wrong thing, although the abs turned off when I unplugged it? Checked wires and looked okay, could be wrong there? New oil in diff, Just trying to get it fixed as quick and cheap as possible. Anybody good advice last things to check before replacing tone ring if I don't have to?
If it is jumping from between 0 and 20 with the truck parked I would not do anything to the rear end other then maybe unplugging the VSS at the rear end.
Also leave the RABS module unplugged.
See if it still does it.
If so you either have a bad power connection or ground to the PSOM or a bad new PSOM.
Did the old PSOM do the same thing?
If yes I would look at the power and grounds.
04-30-2018, 09:42 PM
